diff --git a/Cargo.lock b/Cargo.lock
index 7fc8231..d525de8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -16,6 +16,13 @@ dependencies = [
  "nom",
 ]
 
+[[package]]
+name = "day-03"
+version = "0.0.0"
+dependencies = [
+ "nom",
+]
+
 [[package]]
 name = "memchr"
 version = "2.6.4"
diff --git a/Cargo.toml b/Cargo.toml
index 0215d69..29da117 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,7 +2,8 @@
 resolver = "2"
 members = [
     "day-01",
-    "day-02"
+    "day-02",
+    "day-03"
 ]
 
 [workspace.dependencies]
diff --git a/day-03/Cargo.toml b/day-03/Cargo.toml
new file mode 100644
index 0000000..a3fd72e
--- /dev/null
+++ b/day-03/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "day-03"
+version = "0.0.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+nom.workspace = true
diff --git a/day-03/output.txt b/day-03/output.txt
new file mode 100644
index 0000000..5475b1e
--- /dev/null
+++ b/day-03/output.txt
@@ -0,0 +1,1225 @@
+224
+487
+718
+378
+284
+310
+313
+311
+744
+486
+485
+741
+359
+666
+439
+925
+235
+758
+440
+251
+262
+752
+774
+515
+705
+746
+942
+591
+347
+470
+257
+637
+793
+299
+813
+509
+464
+688
+82
+901
+836
+814
+80
+17
+679
+661
+299
+222
+875
+213
+161
+964
+894
+998
+310
+258
+85
+735
+586
+650
+23
+760
+202
+339
+598
+536
+702
+705
+793
+957
+935
+965
+357
+242
+283
+956
+118
+959
+184
+401
+527
+348
+161
+63
+955
+523
+77
+978
+846
+849
+699
+790
+911
+87
+486
+914
+842
+127
+844
+946
+235
+209
+710
+735
+144
+226
+298
+560
+253
+431
+586
+723
+482
+871
+918
+329
+906
+350
+365
+361
+536
+793
+664
+739
+507
+289
+256
+73
+356
+834
+96
+939
+28
+553
+526
+501
+746
+890
+701
+807
+447
+97
+58
+891
+346
+699
+421
+666
+198
+791
+340
+433
+316
+81
+984
+462
+116
+711
+963
+380
+745
+85
+224
+370
+923
+563
+188
+326
+67
+815
+582
+530
+489
+59
+57
+100
+441
+161
+637
+961
+118
+21
+216
+432
+309
+64
+992
+81
+781
+644
+324
+126
+166
+385
+233
+436
+517
+88
+390
+355
+335
+372
+254
+294
+589
+803
+38
+56
+235
+196
+948
+359
+398
+608
+145
+346
+915
+485
+945
+936
+114
+118
+490
+536
+663
+61
+856
+343
+859
+345
+862
+711
+313
+606
+23
+316
+529
+362
+49
+307
+791
+225
+281
+222
+283
+675
+911
+90
+914
+39
+509
+797
+23
+895
+67
+164
+896
+554
+460
+181
+211
+474
+201
+911
+717
+192
+75
+679
+355
+678
+650
+128
+925
+230
+105
+409
+897
+698
+427
+313
+670
+521
+308
+838
+335
+367
+325
+233
+224
+950
+688
+199
+774
+793
+108
+501
+102
+924
+349
+595
+395
+753
+318
+676
+759
+154
+524
+908
+694
+211
+173
+214
+424
+458
+403
+958
+98
+688
+957
+488
+591
+218
+203
+196
+765
+971
+927
+741
+227
+592
+60
+885
+287
+474
+409
+226
+174
+230
+162
+169
+510
+962
+17
+32
+225
+880
+201
+823
+914
+724
+89
+267
+717
+54
+436
+60
+69
+710
+601
+306
+287
+65
+308
+926
+278
+415
+241
+827
+265
+662
+678
+734
+144
+424
+434
+701
+380
+731
+24
+973
+741
+728
+357
+304
+881
+238
+740
+947
+587
+22
+271
+603
+266
+918
+519
+617
+826
+268
+974
+486
+376
+295
+939
+363
+378
+302
+586
+740
+380
+931
+12
+387
+588
+315
+712
+491
+956
+180
+454
+104
+661
+91
+811
+370
+471
+419
+804
+464
+243
+578
+604
+250
+784
+750
+998
+245
+165
+771
+691
+768
+654
+261
+566
+441
+91
+194
+643
+932
+379
+86
+940
+263
+638
+344
+795
+991
+544
+767
+266
+708
+727
+191
+698
+990
+308
+325
+44
+18
+397
+93
+649
+900
+62
+322
+339
+619
+404
+540
+742
+196
+874
+205
+96
+203
+224
+704
+727
+496
+135
+769
+757
+424
+714
+5
+884
+114
+674
+144
+83
+302
+29
+179
+104
+531
+629
+455
+473
+300
+254
+640
+296
+1
+548
+103
+381
+365
+713
+282
+744
+709
+431
+837
+9
+90
+347
+179
+359
+92
+304
+923
+446
+385
+699
+749
+193
+206
+922
+197
+128
+273
+758
+439
+650
+54
+736
+817
+152
+594
+949
+807
+224
+124
+889
+625
+139
+667
+239
+387
+806
+788
+632
+8
+584
+280
+11
+726
+181
+761
+66
+64
+14
+742
+736
+725
+708
+667
+332
+828
+750
+425
+944
+926
+719
+110
+348
+121
+961
+971
+629
+830
+91
+241
+491
+930
+561
+889
+710
+333
+163
+311
+252
+270
+165
+208
+694
+914
+126
+267
+183
+952
+645
+414
+822
+69
+112
+464
+267
+359
+7
+806
+931
+355
+928
+854
+993
+101
+439
+897
+8
+381
+748
+987
+437
+954
+595
+783
+49
+110
+675
+8
+60
+981
+730
+336
+120
+790
+386
+90
+212
+985
+153
+12
+912
+383
+665
+754
+950
+790
+896
+773
+777
+581
+514
+910
+5
+579
+496
+347
+790
+334
+912
+692
+609
+694
+693
+213
+620
+695
+871
+385
+82
+785
+163
+984
+545
+978
+971
+477
+465
+196
+313
+447
+766
+49
+126
+480
+798
+792
+359
+193
+837
+157
+773
+752
+447
+565
+53
+384
+449
+470
+749
+792
+138
+527
+339
+299
+505
+287
+691
+700
+96
+721
+942
+845
+713
+260
+491
+452
+336
+73
+960
+238
+163
+689
+831
+282
+709
+960
+204
+59
+97
+199
+111
+498
+557
+972
+450
+653
+476
+398
+619
+280
+923
+31
+691
+67
+782
+268
+428
+408
+740
+576
+734
+317
+114
+332
+795
+743
+908
+381
+914
+420
+647
+528
+284
+825
+721
+929
+324
+167
+561
+815
+466
+389
+304
+480
+851
+585
+942
+496
+53
+170
+938
+518
+368
+941
+930
+364
+522
+59
+652
+963
+949
+828
+784
+860
+420
+548
+310
+476
+94
+589
+833
+426
+940
+959
+993
+88
+398
+624
+917
+838
+664
+721
+833
+672
+19
+350
+333
+707
+240
+336
+746
+263
+463
+220
+663
+849
+631
+712
+308
+580
+78
+422
+444
+281
+447
+37
+814
+788
+810
+369
+985
+92
+684
+74
+279
+128
+464
+944
+978
+163
+984
+5
+165
+285
+889
+969
+5
+272
+374
+948
+13
+358
+796
+632
+789
+91
+66
+152
+508
+3
+544
+517
+703
+774
+434
+794
+932
+241
+74
+974
+954
+375
+772
+218
+414
+366
+252
+501
+566
+599
+256
+468
+942
+101
+156
+998
+263
+312
+767
+95
+838
+162
+130
+583
+544
+176
+936
+826
+421
+139
+982
+893
+284
+724
+661
+694
+85
+438
+51
+616
+698
+36
+262
+357
+224
+491
+193
+596
+844
+387
+132
+84
+362
+98
+14
+394
+56
+432
+512
+704
+424
+74
+196
+875
+132
+229
+723
+568
+108
+672
+55
+172
+217
+289
+427
+795
+214
+336
+94
+988
+86
+838
+540
+902
+922
+288
+719
+845
+558
+524
+195
+704
+77
+842
+166
+883
+503
+451
+305
+600
+900
+280
+169
+586
+751
+944
+116
+416
+877
+418
+194
+644
+244
+354
+118
+208
+788
+826
+207
+152
+893
+608
+948
+203
+206
+341
+977
+916
+49
+385
+266
+607
+990
+964
+340
+697
+62
+526
+675
+612
+604
+492
+884
+212
+157
+679
+706
+716
+518
+103
+749
+989
+739
+212
+684
+35
+785
+343
+680
+423
+476
+420
+241
+532
+864
+826
+403
+311
+60
+451
+562
+306
+420
+321
+241
+240
+845
+740
+968
+389
+177
+640
+82
+963
+211
+38
+901
+404
+253
+37
+218
+501
+320
+215
+264
+298
+970
+801
+569
+3
+859
+136
+818
+212
+91
+72
+750
+775
+728
+29
+270
+984
+371
+639
+670
+959
+438
+524
+943
+755
+162
+446
+290
+751
+557
+483
+421
+189
+9
+786
+835
+978
+445
+350
+860
+662
+354
+682
+117
+57
+441
+88
+142
+927
+402
+874
+734
+926
+633
+219
+84
+662
+205
+334
+981
+367
+338
+332
+119
+375
+334
+146
+384
+511
+165
+666
+614
+744
+617
+887
+848
+203
+593
+158
+152
+817
+866
+904
+701
+165
+80
+404
+977
+93
+396
+281
+953
+116
+97
+70
+179
+107
+338
+622
+445
+382
+672
+859
+571
+717
+240
+175
+808
+225
+988
+604
+232
+448
+651
+769
+569
+975
+968
+585
+26
+394
+142
+498
+969
+360
+666
+919
+360
+484
+407
+886
+84
+933
+101
+58
+839
+425
+540658
diff --git a/day-03/src/bin/input.txt b/day-03/src/bin/input.txt
new file mode 100644
index 0000000..94f0d8b
--- /dev/null
+++ b/day-03/src/bin/input.txt
@@ -0,0 +1,140 @@
+..224.....487...................718.....................378............................................284........310......313..........311.
+....*..............................*744....486*485......*......741......@...359.#666...439................*925....*......$..+........@......
+.235................758..440...........................251....*......262.....*..........*......................752......774.......515.......
+.........705%..@746........+..942*591.347.470...#..257.........637...........793.......299..../.....813....509......464......&.........688..
+.....82................................*.../..901.....*..................836.....&............814...*........*..............80...17*....*...
+.../...*...679.661.....299...........222.............875.....213...161............964...894.........998.....310....258.85...........735.586.
+.650..23..#......*.......................................760*........@./........................202...................*.....339.............
+..............598......#.....536....702*.........705..........793......957............./........*...935...........965.......................
+..................*.357...+.....@.......242.......*......283..*...=956.......118.......959...184...*..............*....401*527.....348...161
+.63=...955.523..77......978.846....849..........699..........790........=911.*.....87...............486.........914..............=..........
+.........*.........842......*.......*..................*127....................844...*....946.......................235...209@...710.735....
+...........@.........*.....144....226....298........560.....253.........431......*...586.......723..../...482.......&...................*...
+...........871../918........................+....................329*......%.....906.............*...350.....@...............365.......361..
+......................536............................+..793..........664.....739................507......289.....256%...73..*...............
+.356..834..............*.........96.939..............28.+....=..............*...........................*................$.553..........526.
+...*...*.............501..746....*..-.......=.................890.....+...701..............807........447......97$..%...........58......$...
+.891....346...699...........*.421......+....666......198*791......340.433............#...%...*.......................316........*.....%.....
+..............%........81.984...........462....................../..........116...711....963...$................380.......745...85....224...
+.........370......923..@.....................563...........188+.........326*...................67.815..............*582.....................
+.........*........-........#530.........489........59...................................................#.....57.........100.*.......441*161
+.637*....961...........118...........21*...........@..216+.........................+....432*.*309..64....992.......81......=.781.644........
+.....324.........126......*166...............&...................385*..............233............*................*..436...........*517....
+.88*.........390*................355..335...372....+254..............294...$589........&..803/.....38..-...........56..$....................
+....235.-.........+196...948....*........-................359.........................398.............608..../.................145..346.....
+........915.................-.485.945.................936*................114.............118...............490.536..............*.%........
+.663........61.......856..........+....343....859...............*345.......*...=862............711.............................313.....606..
+........23...$.....@..................*......................316.....529.362.............49......................307*791....................
+225...............281...#..222.....@..283..............675............*.........911*90..-.....914..%39....509...............................
+.......797*....$........23..../...895.............67.......164.896.....554.....................*............=..............460........181...
+...........211.474...............................@...........*....*201..........911.717.#....192.75..679...........$.........*.........=....
+....355.........................&.....................678.650......................*.....128.....*.....*.........925..230...105.............
+....*.......409#.......*897.....698....427.........+....*.......*...............................313...670..521.......*....&.............*308
+...838..335.................367........-..........325....233...224...950......688.....199.774.........................793.108........501....
+...........*..102..924.349...+..595....................................*................&..............395+.....................753.........
+.........318...*......*........*....676...759.154...................524...........908.........694.211................173...........*214..424
+....458........403...........958.98....*........*..............688......957...488..+...........*.../....................................*...
+.......*.............591...............218.....203.....196$.......+....*........*......................765......971......./....927*741..227.
+......592..%60.$.....*.....885/....287...............................474.........409......226.174.......@........*.....230..................
+...............162.169.................510..962..............17......................32@..*...*.................225....................-....
+.....880...................201.....823*........*...914.724.........89...&.......267=.....717.54.436..........60...............&.........69..
+710........601....306.287.....+.........65...308....&...=.../......*.....926..................................*........278.415......-.......
+..............*..*......&..........241.%...................827../.265.............662.678......@...#......@.....$......-............734.144.
+.............424..434.....701.....*........380*731.............24.................*...&........973..741....728..357.........................
+........304.................*...881................238.....740.........947........587...22...........................271*........603....@...
+...................266.....918....................*..........+.519.617..*...826..........*............./268..974.........486.376....*.295...
+...939.........363.*...............378..........302....586........*....740...=..........380........931...........................12.........
+...*..........-.....387...............*..588..............*..../...............315...................-...712..491.........956.....#.........
+.180.454...................104..661...91...*.............811....370......471...-....419....804..........*...................*...............
+.....*.......@../464........%..*............243.....578...................&..........*...........604..250.....784....750....998.............
+.....245....165.................771...................&.......#.691...768....654....261.........................*.......*............566....
+441..................91.....194.......643...932*............379.#....$.......*.................86.............940..263.638...........*......
+...+.............%.../.......#.........*........344...795..................991..........544....*..................*..........767...266......
+.......-..708..727.....191$......*.....698....=...................990................+.....*....308.......@......325.........*.........44...
+...18.397....=.....93.........649.900.........62....-........322.....*.......@......339....619..........404..........540........./....*.....
+..../...............%............................742............*...........196................874.205........96#..............203.224......
+.........704...727.................496.......*........135....769........./.................%....&....*.../..=.........757...................
+........*........*..424..........&........714.5........*...........@....884...............114.......674.144..83..........*302...........%...
+........29....179..*............104..................531....629.455..................473......300....................254..............640...
+..................296.......................................................1........*.......%..............548........*.....103............
+....381...........................365#..713.282.......%744....................../....709...#...=...431...$.*......*.....837.....*9.....*....
+......*.90.....347.179#...................%.......359..........92............304...*.....923.446.......385.699.....749..............193.206.
+....922.+.......*.......-197.....................*.......128........273....@.....758..............439...................650*54.736#.........
+................817..-..........152..594..949..807.......$...224...*.....124............889.......=...................................625...
+....139....667......239........*...........*.......387........%..806........../...........*..788....632...........=8......584-......*.%.....
+...........*.................280...........11.........*726............181......761..-....66.....%....-................64...........14.......
+............742.736.725..........708.667..........332.......828*750......-.........425.......................944.....*...................926
+.719...110...........*.....348...=..........121......*........................................*.......961.....*.......971...........+.......
+..../.....*629........830..*............91....&..241..491...930............561................889....*....710.333..............163...311....
+......%...................252.../..................*...........*270.......................165.....208.......*..................../.......694
+...914...126...267.183........952..$645......414.822................................69.......-..........=..112.464..267....359..........*...
+.............7*..........................806.../.....931.....*.....355..............*....928...........854.........-..............*993...101
+439.897...........%...........8......381...*........*....748..987....*............437.......*....954.......................*................
+.......*595....783........49.....110.$...675...8...60.....=........981........&..........730....*.............336.......120.790..........386
+............90..............*212...*..........*.......985.....153........*..12...912*383......665.....754.....-.....................950.....
+......790#.*........896@.........773....777..581..514*....910.....5.....579.............................=.......#.....................*.....
+...&.......496...........347..............*...............*...................../............................790..............334......912..
+692............609....&.......694..........693...213....620......695......871..385.......82..........785.......................*..163.......
+.........#....*......984.........*.................=............*.......................................*.545...-............978.....*......
+......971...477.............465......196*313..........447.......766......49.......126*480.............798......792..359*193...........837...
+................157...........+..................773.=..............752$....................447*565..........................*53............
+.384%..........@.........449............470..749...@.........@792..............138..527.......................339.....299.505...........287.
+......691........700........@......96..........*........721*.....................@....*...942......845........*......-.........713..........
+.....*......260/...*...........................491..452.....336.......................73....+..960..........238...........163$..&...=.@.....
+....689.............831...282....709.960.............=.............204............................#..............59...97..........199..111..
+........................$........../........-....498......................557....&...........972............450.............................
+.............653........476...398.........619...*.....*280..923..............*31..691.........*........=...*.....67......782................
+..............*....%..........*.........+......268...........&........428....................408....740....576....*.......*.........$.......
+....-../...734......317.114.332...795...743.........................-..=..908...........381.......................914...420.*647....528.....
+..284.825...............*......................721/.=929.........324.....*....167.561...*.....815*466.......................................
+..............389..304.480.......851..@....585..............942%......#.496....*....-.53................170....938*..........518............
+........368..*.....@..............*....941..+.......*...............930.........364.......522......................59.........+....$....652.
+...........+.963...................949...........828.784......860............*......420.....*..................*......548...........310.*...
+.....476...............*...............=...94.+..................&........589.833....*..426.940.....&.....959.993.&88....................398
+.......*................624....917...838..*...664.......721........................833...$.......672......$............19...................
+....350.......................&....=..............333.................707....................................240..336....=...746.263..$463..
+.........................-.........220.....663...../.............*849..#..631.....712....=.../...308.580.............*..........*...........
+.78@......../..........422....444.............*...............281............*...*....447..37.......*................814....................
+........./...788...810.........&..............369..985....-................92................................684...............74...........
+......279.........*......128/....464........#...../......944........978...............163..984*5.@............+.......165......*....285.....
+..................889.............*.......969........................%.......5......&....$........272....................*......374.........
+.........&..............@948..*..13.358........796.............632............*....789........91*..............*66........152...............
+........508...+..............3...........544.....$.517.....703....*774.......434............/....794........932.............................
+...$...........241.....74...........974..*...954............*.......................375..772...........218.........414...........*366....252
+.501..566...............*..........*....599.....#........256.....468@..942.101.........*..........156...*.............*.......998...........
+...../.............263.312....+..767..............#.........................*...&95..838.162=.....+....130.........583..544.......176.......
+............................936......826.......421.......-139.......982...893.......................*..................*........./..........
+.284.....=724...................661.$....694........85..........438.............51...............616.698.*36.....262......357+........224...
+....@..........491........+........................@......193......*596...........%../844...387.................$.....132.........%.........
+.......84..............362.................................*..98..........&................*....14....394..........$..............56........
+.........*432.....512................704......424.............*............74........196%..875...*.....*............132.......229...........
+..............723*.........568........*..108........672......55.172...217.........................289.427........................*..........
+.........#795.........214....*.336...94....*....988................%..&.............*86......*...............838&.......540.......902.......
+.922...........288........719.....*........845...&..558......#...................524......195.704.....................................77....
+...*....842....../...166........883...-................*503..451..305../....600............................900..280.....*169...586..........
+751....*.........../.*......944......116....416.........................877....*....418...194........644..*....=.....244..........#.....354.
+.......118......208...................................788...................826........$....$...207.....@..152...........893*608.......&....
+..948.......................203../....206.............*....341./977.916.........49...#........@....-............+385........................
+...*......266.................*...607...@.990......964..............-..........*.....340...697........62..............526.....-.............
+..675.....*..........612....604.............*..............492.884...........212...............*157....*...679.........*....706...716%.518..
+......103.749..989...*...................739..............$......=..=..................212..684.....35.......*.........785..............+...
+..343*......../.......680.....................*423.................476....&....420..............241..*......532.....+.......864$.....&......
+..................826........403..311...60.451.............+...........562....../.......306.......*..............420..................321...
+...241..............*...........+..=....@......*240.......845....@.........740.................968..389.177*...................640..........
+......*82...........963...211%...............38...............901.....404.........&..253..............-.....37.........218.501...*....320...
+....*...........................#215...264......298........................*970..801....*....569...............3.......*......%..859.*......
+.136.818...212...........91*72........*.........-...750.....775*728.29.270...............984.&...371..........*.........639..........670....
+...........*.../959................438.....524......*...943.........*................755...................162.................446#.........
+..........290.............751................*.....557..*...483.............421.........*............189.%................/.................
+....................9.786..-......835.......978........445.%..........350........860..662.......#...*....354........*.....682...............
+.117..57+....441...*....+............................................../............*.........88....142..........%.927......................
+...*...........*..402....................874.....734.926$../...............*633......219.84/............662...205...................334.....
+...981........367........338...332/.........=......*......119....375#.334.......146..............%.....$................384.............-511
+........165................=....................666.....................#..614.....-..%744..617.887.......848*..............................
+...........*.203.593...158....*..........152..............+817.....866.......&...............*......../.......904........701.165.80.........
+404..977.93..*....*....*...396.281......*....953....*................*.........116..97.70=..179....107..338................$...*....622.....
+......=.....445........................382.....*...672................859......*...%....................&..........-.571......717....*......
+..................240............175..........808..............225..........988............/604..............232.448..*..651......769.......
+.........569*....*........975*.....*....968..............585.....*................26.................................394....@.142...........
+......*......498..969.........360.666...%.........................919.......360........-.*.........%...................................484..
+...407................886...................................84......................933...101....58........839..425.........................
\ No newline at end of file
diff --git a/day-03/src/bin/part1.rs b/day-03/src/bin/part1.rs
new file mode 100644
index 0000000..208d56b
--- /dev/null
+++ b/day-03/src/bin/part1.rs
@@ -0,0 +1,62 @@
+use nom::{branch::alt, bytes::complete::is_not, character::complete::digit1, multi::many1};
+use std::collections::HashSet;
+
+fn main() {
+    println!("{}", part1(include_str!("./input.txt")));
+}
+
+fn part1(input: &str) -> u32 {
+    let mut symbols = HashSet::new();
+    input
+        .lines()
+        .enumerate()
+        .flat_map(|l| l.1.chars().enumerate().map(move |c| (l.0, c.0, c.1)))
+        .filter(|(_, _, c)| !c.is_ascii_digit() && *c != '.')
+        .for_each(|(y, x, _)| {
+            symbols.insert((x, y));
+        });
+
+    input
+        .lines()
+        .enumerate()
+        .map(|(y, l)| line(l, y, &symbols))
+        .sum()
+}
+
+fn line(i: &str, y: usize, symbols: &HashSet<(usize, usize)>) -> u32 {
+    many1(alt((
+        is_not("0123456789"),
+        digit1::<&str, nom::error::Error<&str>>,
+    )))(i)
+    .unwrap()
+    .1
+    .into_iter()
+    .fold((0, 0), |(pos, sum), cur| {
+        if let Ok(num) = cur.parse::<u32>() {
+            let y_minus_1 = y.checked_sub(1).unwrap_or(y + 1);
+            let pos_minus_1 = usize::checked_sub(pos, 1).unwrap_or(pos);
+
+            let symbol_y = (pos_minus_1..=pos + cur.len())
+                .any(|x| symbols.contains(&(x, y + 1)) || symbols.contains(&(x, y_minus_1)));
+            let symbol_x =
+                symbols.contains(&(pos_minus_1, y)) || symbols.contains(&(pos + cur.len(), y));
+
+            let value = if symbol_y || symbol_x { num } else { 0 };
+
+            (pos + cur.len(), sum + value)
+        } else {
+            (pos + cur.len(), sum)
+        }
+    })
+    .1
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part1() {
+        assert_eq!(part1("467..114..\n...*......\n..35..633.\n......#...\n617*......\n.....+.58.\n..592.....\n......755.\n...$.*....\n.664.598.."), 4361);
+    }
+}
diff --git a/day-03/src/bin/part2.rs b/day-03/src/bin/part2.rs
new file mode 100644
index 0000000..deaca48
--- /dev/null
+++ b/day-03/src/bin/part2.rs
@@ -0,0 +1,80 @@
+use nom::{branch::alt, bytes::complete::is_not, character::complete::digit1, multi::many1};
+use std::{collections::HashMap, sync::Mutex};
+
+fn main() {
+    println!("{}", part2(include_str!("./input.txt")));
+}
+
+fn part2(input: &str) -> u32 {
+    let mut gears = HashMap::new();
+    input
+        .lines()
+        .enumerate()
+        .flat_map(|l| l.1.chars().enumerate().map(move |c| (l.0, c.0, c.1)))
+        .filter(|(_, _, c)| *c == '*')
+        .for_each(|(y, x, _)| {
+            gears.insert((x, y), Mutex::new(Vec::new()));
+        });
+
+    input
+        .lines()
+        .enumerate()
+        .for_each(|(y, l)| line(l, y, &gears));
+
+    gears
+        .values()
+        .map(|nums_mutex| {
+            let mut nums = nums_mutex.lock().unwrap();
+            nums.sort();
+            nums.dedup();
+            if nums.len() == 2 {
+                nums[0] * nums[1]
+            } else {
+                0
+            }
+        })
+        .sum()
+}
+
+fn line(i: &str, y: usize, gears: &HashMap<(usize, usize), Mutex<Vec<u32>>>) {
+    many1(alt((
+        is_not("0123456789"),
+        digit1::<&str, nom::error::Error<&str>>,
+    )))(i)
+    .unwrap()
+    .1
+    .into_iter()
+    .fold(0, |pos, cur| {
+        if let Ok(num) = cur.parse::<u32>() {
+            let y_minus_1 = y.checked_sub(1).unwrap_or(y + 1);
+            let pos_minus_1 = usize::checked_sub(pos, 1).unwrap_or(pos);
+
+            (pos_minus_1..=pos + cur.len()).for_each(|x| {
+                if let Some(v) = gears.get(&(x, y + 1)) {
+                    v.lock().unwrap().push(num)
+                }
+                if let Some(v) = gears.get(&(x, y_minus_1)) {
+                    v.lock().unwrap().push(num)
+                }
+            });
+
+            if let Some(v) = gears.get(&(pos_minus_1, y)) {
+                v.lock().unwrap().push(num)
+            }
+            if let Some(v) = gears.get(&(pos + cur.len(), y)) {
+                v.lock().unwrap().push(num)
+            }
+        }
+        pos + cur.len()
+    });
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part2() {
+        assert_eq!(part2("467..114..\n...*......\n..35..633.\n......#...\n617*......\n.....+.58.\n..592.....\n......755.\n...$.*....\n.664.598.."), 467835);
+    }
+}