diff --git a/2021/Cargo.toml b/2021/Cargo.toml
index ce383da..b406b65 100644
--- a/2021/Cargo.toml
+++ b/2021/Cargo.toml
@@ -4,6 +4,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+fnv = "1.0.7"
 itertools = "0.10"
 paste = "1.0"
 
diff --git a/2021/inputs/day05 b/2021/inputs/day05
new file mode 100644
index 0000000..d6a5213
--- /dev/null
+++ b/2021/inputs/day05
@@ -0,0 +1,500 @@
+456,846 -> 221,846
+980,926 -> 73,19
+682,930 -> 562,930
+766,592 -> 274,100
+247,685 -> 247,21
+106,800 -> 635,800
+953,340 -> 135,340
+293,223 -> 293,12
+454,196 -> 454,463
+886,766 -> 164,766
+592,590 -> 192,590
+436,982 -> 436,545
+731,571 -> 420,260
+741,11 -> 466,11
+727,541 -> 579,541
+341,553 -> 25,553
+942,470 -> 942,196
+203,600 -> 203,647
+965,595 -> 949,611
+554,306 -> 554,401
+902,438 -> 902,728
+864,609 -> 525,270
+187,790 -> 187,323
+956,950 -> 427,950
+847,554 -> 422,554
+935,900 -> 701,900
+192,854 -> 866,180
+512,946 -> 543,915
+978,979 -> 491,979
+708,61 -> 708,878
+738,508 -> 282,52
+23,25 -> 841,843
+204,750 -> 204,797
+703,500 -> 703,419
+14,311 -> 694,311
+646,301 -> 785,301
+397,168 -> 439,168
+680,931 -> 561,812
+540,448 -> 90,448
+706,668 -> 91,53
+848,319 -> 318,319
+198,948 -> 198,307
+686,58 -> 686,541
+867,234 -> 867,498
+134,125 -> 134,688
+824,566 -> 53,566
+437,167 -> 276,167
+94,65 -> 638,609
+36,971 -> 971,36
+494,330 -> 494,197
+920,438 -> 920,364
+698,84 -> 49,733
+59,842 -> 59,876
+328,577 -> 328,677
+757,701 -> 134,78
+466,274 -> 135,605
+81,925 -> 988,18
+40,142 -> 882,984
+50,96 -> 882,928
+782,47 -> 782,427
+247,599 -> 24,599
+112,812 -> 191,733
+487,198 -> 144,198
+327,663 -> 327,756
+117,76 -> 688,76
+530,71 -> 530,958
+558,602 -> 671,489
+677,830 -> 677,556
+529,669 -> 349,669
+336,966 -> 341,971
+20,31 -> 851,862
+423,880 -> 423,573
+521,657 -> 552,657
+412,822 -> 18,428
+423,311 -> 423,105
+381,614 -> 705,614
+521,248 -> 394,121
+286,47 -> 286,403
+286,27 -> 711,452
+347,61 -> 489,61
+760,454 -> 760,954
+746,573 -> 911,573
+839,933 -> 839,776
+124,815 -> 290,649
+577,848 -> 419,848
+393,206 -> 410,206
+364,755 -> 881,755
+788,68 -> 788,215
+94,798 -> 192,798
+292,250 -> 453,250
+601,545 -> 293,237
+438,923 -> 438,655
+70,757 -> 887,757
+184,402 -> 818,402
+586,49 -> 103,49
+202,315 -> 735,315
+534,504 -> 534,523
+367,236 -> 367,736
+24,163 -> 24,240
+185,426 -> 634,875
+485,189 -> 39,189
+556,30 -> 374,30
+969,821 -> 676,528
+254,435 -> 254,43
+290,615 -> 741,164
+345,601 -> 120,826
+224,641 -> 887,641
+190,716 -> 581,325
+552,646 -> 552,393
+413,177 -> 413,103
+397,900 -> 360,900
+138,980 -> 138,55
+909,891 -> 909,593
+926,986 -> 79,139
+954,67 -> 53,968
+180,30 -> 595,30
+823,165 -> 823,660
+285,176 -> 375,176
+915,826 -> 184,95
+735,230 -> 667,230
+934,865 -> 917,865
+48,602 -> 737,602
+477,319 -> 385,411
+981,17 -> 11,987
+458,401 -> 24,401
+118,415 -> 849,415
+176,678 -> 176,852
+567,753 -> 567,37
+285,868 -> 830,323
+555,623 -> 822,623
+522,546 -> 674,546
+880,21 -> 23,878
+591,103 -> 591,407
+434,64 -> 434,401
+245,968 -> 275,968
+726,510 -> 450,786
+768,366 -> 768,738
+488,745 -> 488,94
+675,674 -> 675,705
+618,237 -> 265,237
+802,709 -> 802,59
+144,696 -> 144,542
+547,381 -> 547,799
+78,667 -> 78,916
+409,271 -> 302,271
+294,694 -> 938,50
+140,571 -> 97,571
+682,875 -> 682,534
+748,816 -> 748,183
+84,622 -> 84,258
+485,696 -> 582,599
+909,233 -> 954,233
+203,711 -> 203,350
+335,904 -> 455,904
+578,778 -> 578,21
+830,954 -> 902,954
+78,252 -> 78,682
+920,220 -> 684,220
+309,301 -> 104,301
+270,795 -> 270,919
+906,479 -> 304,479
+627,164 -> 627,986
+122,960 -> 915,167
+664,916 -> 770,810
+692,810 -> 826,810
+981,951 -> 192,162
+183,423 -> 809,423
+632,464 -> 567,464
+94,266 -> 94,587
+261,770 -> 569,770
+51,403 -> 466,818
+631,645 -> 187,645
+141,238 -> 141,145
+357,21 -> 173,21
+138,248 -> 839,949
+889,957 -> 807,957
+399,431 -> 105,725
+548,331 -> 548,821
+790,844 -> 43,97
+675,671 -> 221,671
+874,143 -> 620,397
+205,435 -> 205,546
+521,434 -> 822,133
+141,86 -> 257,86
+427,28 -> 290,165
+49,694 -> 567,694
+846,344 -> 266,924
+425,910 -> 433,918
+956,498 -> 485,27
+798,498 -> 798,634
+879,13 -> 766,126
+737,475 -> 737,425
+338,473 -> 425,386
+510,615 -> 214,319
+758,415 -> 758,490
+969,208 -> 239,938
+917,188 -> 917,528
+34,820 -> 806,820
+85,633 -> 857,633
+262,355 -> 262,748
+373,784 -> 971,186
+146,577 -> 60,663
+613,570 -> 613,199
+300,319 -> 300,108
+764,171 -> 764,17
+555,921 -> 555,825
+241,197 -> 770,197
+600,832 -> 600,807
+934,987 -> 20,73
+960,730 -> 837,730
+976,50 -> 46,980
+829,834 -> 153,158
+785,835 -> 785,58
+586,633 -> 689,736
+804,250 -> 348,706
+226,539 -> 16,539
+411,940 -> 98,940
+289,589 -> 893,589
+738,616 -> 738,55
+225,54 -> 542,54
+793,246 -> 303,736
+332,752 -> 984,100
+413,18 -> 839,444
+840,122 -> 840,233
+989,970 -> 215,196
+329,361 -> 573,605
+242,537 -> 242,619
+943,898 -> 943,535
+469,865 -> 501,833
+226,717 -> 196,687
+819,803 -> 712,803
+532,663 -> 532,672
+61,931 -> 940,52
+623,218 -> 274,567
+281,326 -> 281,790
+815,176 -> 679,176
+790,862 -> 942,710
+18,771 -> 18,514
+479,377 -> 309,377
+704,402 -> 704,150
+961,335 -> 492,335
+745,829 -> 745,477
+556,543 -> 771,543
+832,336 -> 917,251
+742,755 -> 742,174
+206,735 -> 493,735
+151,216 -> 312,55
+445,157 -> 615,157
+781,143 -> 781,76
+833,717 -> 514,398
+357,14 -> 357,36
+771,405 -> 771,422
+662,886 -> 169,886
+689,990 -> 22,990
+680,445 -> 379,445
+92,369 -> 502,779
+64,948 -> 64,363
+295,957 -> 976,276
+113,920 -> 634,399
+542,662 -> 305,899
+566,514 -> 566,645
+528,106 -> 549,106
+205,367 -> 821,367
+313,105 -> 313,928
+532,177 -> 532,664
+862,773 -> 905,816
+800,796 -> 911,796
+870,80 -> 11,939
+188,900 -> 154,900
+420,509 -> 520,609
+540,863 -> 28,863
+31,72 -> 78,72
+823,648 -> 503,648
+879,252 -> 606,252
+677,117 -> 677,507
+743,303 -> 196,850
+220,491 -> 220,891
+216,815 -> 577,815
+540,819 -> 745,819
+152,721 -> 382,721
+280,745 -> 985,745
+479,367 -> 358,488
+913,413 -> 649,413
+40,678 -> 817,678
+467,533 -> 467,214
+132,68 -> 843,779
+519,109 -> 669,259
+619,791 -> 221,791
+114,622 -> 628,622
+951,636 -> 866,636
+172,569 -> 775,569
+244,972 -> 173,972
+283,64 -> 739,520
+68,604 -> 68,156
+529,30 -> 529,925
+813,883 -> 137,883
+893,231 -> 629,231
+673,658 -> 673,389
+725,899 -> 218,899
+317,318 -> 105,318
+82,706 -> 100,688
+222,227 -> 440,227
+810,371 -> 810,985
+414,321 -> 289,446
+901,158 -> 260,799
+198,967 -> 717,448
+928,454 -> 875,454
+974,437 -> 974,764
+657,13 -> 760,13
+498,966 -> 976,966
+66,104 -> 66,15
+773,569 -> 980,362
+420,496 -> 403,513
+57,920 -> 85,920
+879,551 -> 879,662
+98,395 -> 98,398
+483,685 -> 483,55
+222,935 -> 586,935
+89,926 -> 807,208
+744,160 -> 744,462
+588,973 -> 588,548
+312,572 -> 38,298
+27,131 -> 552,656
+591,935 -> 591,86
+907,478 -> 907,279
+981,75 -> 981,972
+316,947 -> 935,947
+906,38 -> 906,216
+374,521 -> 345,550
+579,29 -> 579,107
+444,636 -> 444,557
+458,608 -> 830,980
+479,839 -> 155,515
+766,600 -> 766,71
+976,965 -> 31,20
+928,49 -> 269,708
+787,238 -> 787,983
+583,742 -> 112,742
+966,268 -> 554,680
+671,354 -> 671,966
+274,340 -> 274,894
+673,185 -> 607,185
+73,171 -> 874,171
+861,526 -> 861,410
+739,591 -> 739,138
+209,355 -> 209,146
+286,501 -> 887,501
+495,902 -> 700,902
+192,889 -> 821,260
+400,21 -> 154,21
+861,301 -> 325,301
+552,990 -> 511,990
+908,21 -> 11,918
+127,724 -> 821,30
+935,46 -> 170,811
+947,91 -> 374,91
+625,420 -> 265,60
+214,228 -> 546,228
+375,547 -> 715,887
+516,350 -> 870,350
+610,138 -> 665,193
+214,621 -> 678,621
+497,248 -> 600,145
+549,558 -> 576,558
+364,537 -> 364,312
+840,324 -> 310,854
+441,945 -> 441,458
+459,531 -> 459,100
+937,113 -> 150,900
+277,405 -> 259,405
+409,527 -> 409,359
+534,766 -> 534,740
+534,934 -> 681,934
+456,419 -> 83,419
+871,986 -> 873,986
+14,59 -> 916,961
+911,963 -> 971,963
+25,325 -> 139,211
+937,184 -> 354,767
+460,416 -> 289,245
+193,171 -> 861,839
+840,299 -> 840,911
+531,45 -> 531,619
+599,315 -> 455,315
+455,97 -> 455,811
+38,748 -> 392,748
+841,79 -> 841,88
+105,571 -> 105,545
+801,458 -> 344,458
+491,535 -> 558,535
+835,814 -> 223,202
+563,85 -> 405,85
+410,396 -> 600,396
+273,670 -> 818,125
+671,647 -> 817,647
+46,892 -> 678,260
+456,736 -> 110,736
+962,941 -> 619,598
+388,406 -> 53,71
+558,895 -> 227,564
+944,182 -> 807,319
+484,898 -> 59,473
+808,214 -> 488,534
+451,679 -> 155,383
+858,931 -> 381,931
+723,377 -> 723,281
+694,283 -> 182,795
+385,191 -> 320,256
+33,380 -> 584,931
+480,91 -> 817,91
+677,91 -> 677,126
+291,651 -> 760,182
+832,962 -> 153,283
+38,60 -> 479,501
+249,350 -> 789,350
+603,341 -> 266,678
+52,303 -> 52,102
+911,201 -> 559,201
+46,210 -> 46,275
+960,212 -> 554,212
+375,374 -> 169,580
+10,10 -> 989,989
+844,140 -> 40,944
+916,408 -> 916,815
+834,401 -> 834,169
+553,479 -> 784,248
+543,452 -> 543,848
+854,910 -> 334,390
+685,491 -> 793,491
+552,943 -> 709,943
+723,367 -> 124,367
+95,55 -> 881,841
+155,267 -> 573,267
+59,357 -> 84,357
+218,435 -> 218,344
+491,584 -> 491,649
+676,445 -> 676,333
+361,618 -> 783,618
+220,295 -> 220,267
+668,758 -> 299,389
+965,845 -> 674,845
+285,603 -> 47,603
+853,417 -> 853,757
+859,906 -> 856,906
+55,364 -> 753,364
+893,474 -> 978,474
+602,32 -> 58,576
+171,445 -> 96,370
+214,592 -> 214,286
+400,946 -> 745,946
+559,37 -> 112,484
+624,510 -> 90,510
+329,714 -> 329,850
+458,287 -> 657,287
+99,385 -> 99,949
+50,736 -> 719,67
+273,195 -> 273,306
+490,902 -> 490,798
+619,131 -> 921,131
+266,652 -> 266,730
+745,661 -> 745,555
+311,878 -> 311,679
+491,982 -> 643,830
+735,875 -> 816,875
+936,353 -> 936,529
+792,467 -> 565,467
+141,140 -> 141,988
+98,171 -> 414,487
+257,259 -> 257,484
+24,41 -> 969,986
+302,453 -> 223,453
+807,363 -> 492,678
+823,22 -> 835,10
+301,94 -> 399,94
+946,110 -> 248,808
+983,985 -> 21,23
+510,145 -> 510,58
+13,661 -> 13,639
+218,260 -> 218,54
+475,846 -> 475,770
+458,644 -> 458,529
+912,934 -> 912,136
+152,823 -> 550,823
+136,470 -> 443,470
+253,871 -> 905,219
+765,212 -> 793,240
+11,402 -> 11,42
+348,813 -> 348,768
+368,321 -> 823,776
+343,495 -> 343,809
+117,616 -> 117,273
+92,92 -> 732,92
+914,31 -> 28,917
+259,944 -> 214,944
+630,759 -> 462,759
+134,653 -> 134,610
+14,989 -> 988,15
+139,181 -> 139,451
+598,636 -> 598,442
+263,42 -> 686,465
diff --git a/2021/src/bin/day05.rs b/2021/src/bin/day05.rs
new file mode 100644
index 0000000..77e3b89
--- /dev/null
+++ b/2021/src/bin/day05.rs
@@ -0,0 +1,76 @@
+#![feature(test)]
+extern crate test;
+use aoc2021::common::*;
+use fnv::FnvHashMap;
+use itertools::Itertools;
+use std::collections::HashMap;
+
+const DAY: usize = 5;
+type Parsed = Vec<((usize, usize), (usize, usize))>;
+
+fn parse_input(raw: &str) -> Parsed {
+    raw.lines()
+        .filter_map(|line| line.split_once(" -> "))
+        .filter_map(|(c1, c2)| c1.split_once(',').zip(c2.split_once(',')))
+        .map(|((x1, y1), (x2, y2))| ((x1.parse().unwrap(), y1.parse().unwrap()), (x2.parse().unwrap(), y2.parse().unwrap())))
+        .collect()
+}
+
+fn part1(parsed: &Parsed) -> usize {
+    let mut map: HashMap<_, _, _> = FnvHashMap::default();
+    parsed
+        .iter()
+        .flat_map(|cs| match cs {
+            ((x1, y1), (x2, y2)) if x1 == x2 => (*y1.min(y2)..=*y1.max(y2)).map(|y| (*x1, y)).collect(),
+            ((x1, y1), (x2, y2)) if y1 == y2 => (*x1.min(x2)..=*x1.max(x2)).map(|x| (x, *y1)).collect(),
+            _ => vec![],
+        })
+        .for_each(|c| *map.entry(c).or_insert(0) += 1);
+    map.values().filter(|&&n| n > 1).count()
+}
+
+fn part2(parsed: &Parsed) -> usize {
+    let mut map: HashMap<_, _, _> = FnvHashMap::default();
+    parsed
+        .iter()
+        .flat_map(|cs| match cs {
+            ((x1, y1), (x2, y2)) if x1 == x2 => (*y1.min(y2)..=*y1.max(y2)).map(|y| (*x1, y)).collect_vec(),
+            ((x1, y1), (x2, y2)) if y1 == y2 => (*x1.min(x2)..=*x1.max(x2)).map(|x| (x, *y1)).collect(),
+            ((x1, y1), (x2, y2)) if x1 < x2 && y1 < y2 => (*x1..=*x2).zip(*y1..=*y2).collect(),
+            ((x1, y1), (x2, y2)) if x1 < x2 && y1 > y2 => (*x1..=*x2).zip((*y2..=*y1).rev()).collect(),
+            ((x1, y1), (x2, y2)) if x1 > x2 && y1 < y2 => (*x2..=*x1).rev().zip(*y1..=*y2).collect(),
+            ((x1, y1), (x2, y2)) if x1 > x2 && y1 > y2 => (*x2..=*x1).rev().zip((*y2..=*y1).rev()).collect(),
+            _ => unreachable!(),
+        })
+        .for_each(|c| *map.entry(c).or_insert(0) += 1);
+    map.values().filter(|&&n| n > 1).count()
+}
+
+fn main() {
+    let input = parse_input(&read_file(DAY));
+    println!("Part 1: {}", part1(&input));
+    println!("Part 2: {}", part2(&input));
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use aoc2021::*;
+
+    const TEST_INPUT: &str = "0,9 -> 5,9
+8,0 -> 0,8
+9,4 -> 3,4
+2,2 -> 2,1
+7,0 -> 7,4
+6,4 -> 2,0
+0,9 -> 2,9
+3,4 -> 1,4
+0,0 -> 8,8
+5,5 -> 8,2";
+
+    test!(part1() == 5);
+    test!(part2() == 12);
+    bench!(part1() == 5280);
+    bench!(part2() == 16716);
+    bench_input!(Vec::len => 500);
+}