The Calendar hole will go live in approximately 13 days. Why not try and solve it ahead of time?
ISBN in Python in chars. Achievements Cheevos Holes Languages Medals Miscellaneous All Holes 12 Days of Christmas 24 Game 99 Bottles of Beer Abundant Numbers Abundant Numbers (Long) Arabic to Roman Arithmetic Numbers Arrows Ascending Primes ASCII Table Billiards brainfuck Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz CSS Colors Cubes Day of Week DFA Simulator Diamonds Divisors Emirp Numbers Emirp Numbers (Long) Emojify Evil Numbers Evil Numbers (Long) Factorial Factorisation Farey Sequence Fibonacci Fizz Buzz Foo Fizz Buzz Bar Forsyth–Edwards Notation Fractions Game of Life Gijswijt’s Sequence Happy Numbers Happy Numbers (Long) Hexdump Hilbert Curve Intersection Inventory Sequence ISBN Jacobi Symbol Kaprekar Numbers Kolakoski Constant Kolakoski Sequence Leap Years Levenshtein Distance Leyland Numbers ln 2 Look and Say Lucky Numbers Lucky Tickets Mahjong Mandelbrot Maze Medal Tally Minesweeper Morse Decoder Morse Encoder Musical Chords N Queens Niven Numbers Niven Numbers (Long) Number Spiral Odious Numbers Odious Numbers (Long) Ordinal Numbers PalindromemordnilaP Pangram Grep Partition Numbers Pascal’s Triangle Pernicious Numbers Pernicious Numbers (Long) Poker Polyominoes Prime Numbers Prime Numbers (Long) Proximity Grid QR Decoder Quine Recamán Repeating Decimals Reverse Polish Notation Reversi Rijndael S-box Rock-paper-scissors-Spock-lizard Roman to Arabic ROT13 Rule 110 Scrambled Sort Set Seven Segment SI Units Sierpiński Triangle Smith Numbers Spelling Numbers Star Wars GPT Star Wars Opening Crawl Sudoku Sudoku (Fill-in) Ten-pin Bowling Tic-tac-toe Time Distance Tongue-twisters Topological Sort Tower of Hanoi Transpose Sentence Trinomial Triangle United States Vampire Numbers Van Eck Sequence Zeckendorf Representation Zodiac Signs γ λ π τ φ √2 𝑒 Apéry’s Constant Binary Lambda Calculus Calendar Connect Four Continued Fractions Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers Multitap Input NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial All Languages ><> Assembly AWK Bash BASIC Berry brainfuck C C# C++ Civet Clojure COBOL Coconut Common Lisp Crystal D Dart Elixir Erlang F# Factor Forth Fortran Gleam Go GolfScript Groovy Haskell Hexagony J Janet Java JavaScript jq Julia K Kotlin Lua Nim OCaml Pascal Perl PHP PowerShell Prolog Python R Raku Rockstar Ruby Rust Scheme sed SQL Swift Tcl TeX V VimL Wren Zig 05AB1E ALGOL 68 APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Bytes Chars Scoring Bytes Chars Language All ><> Assembly AWK Bash BASIC Berry brainfuck C C# C++ Civet Clojure COBOL Coconut Common Lisp Crystal D Dart Elixir Erlang F# Factor Forth Fortran Gleam Go GolfScript Groovy Haskell Hexagony J Janet Java JavaScript jq Julia K Kotlin Lua Nim OCaml Pascal Perl PHP PowerShell Prolog Python R Raku Rockstar Ruby Rust Scheme sed SQL Swift Tcl TeX V VimL Wren Zig Experimental Language 05AB1E ALGOL 68 APL Arturo Befunge BQN CJam CoffeeScript Egel Fennel Harbour Hare Haxe Hush Hy iogii Knight Luau Odin Picat Qore Racket Rebol Rexx Scala Squirrel Stax Uiua Umka Vala Vyxal Hole All 12 Days of Christmas 24 Game 99 Bottles of Beer Abundant Numbers Abundant Numbers (Long) Arabic to Roman Arithmetic Numbers Arrows Ascending Primes ASCII Table Billiards brainfuck Card Number Validation Catalan Numbers Catalan’s Constant Christmas Trees Collatz CSS Colors Cubes Day of Week DFA Simulator Diamonds Divisors Emirp Numbers Emirp Numbers (Long) Emojify Evil Numbers Evil Numbers (Long) Factorial Factorisation Farey Sequence Fibonacci Fizz Buzz Foo Fizz Buzz Bar Forsyth–Edwards Notation Fractions Game of Life Gijswijt’s Sequence Happy Numbers Happy Numbers (Long) Hexdump Hilbert Curve Intersection Inventory Sequence ISBN Jacobi Symbol Kaprekar Numbers Kolakoski Constant Kolakoski Sequence Leap Years Levenshtein Distance Leyland Numbers ln 2 Look and Say Lucky Numbers Lucky Tickets Mahjong Mandelbrot Maze Medal Tally Minesweeper Morse Decoder Morse Encoder Musical Chords N Queens Niven Numbers Niven Numbers (Long) Number Spiral Odious Numbers Odious Numbers (Long) Ordinal Numbers PalindromemordnilaP Pangram Grep Partition Numbers Pascal’s Triangle Pernicious Numbers Pernicious Numbers (Long) Poker Polyominoes Prime Numbers Prime Numbers (Long) Proximity Grid QR Decoder Quine Recamán Repeating Decimals Reverse Polish Notation Reversi Rijndael S-box Rock-paper-scissors-Spock-lizard Roman to Arabic ROT13 Rule 110 Scrambled Sort Set Seven Segment SI Units Sierpiński Triangle Smith Numbers Spelling Numbers Star Wars GPT Star Wars Opening Crawl Sudoku Sudoku (Fill-in) Ten-pin Bowling Tic-tac-toe Time Distance Tongue-twisters Topological Sort Tower of Hanoi Transpose Sentence Trinomial Triangle United States Vampire Numbers Van Eck Sequence Zeckendorf Representation Zodiac Signs γ λ π τ φ √2 𝑒 Experimental Hole Apéry’s Constant Binary Lambda Calculus Calendar Connect Four Continued Fractions Crossword CSS Colors (Inverse) CSS Grid Ellipse Perimeters Flags Floyd-Steinberg Dithering Gray Code Decoder Gray Code Encoder Hexagonal Spiral Highly Composite Numbers Multitap Input NFA Simulator Numbrix Odd Polyomino Tiling p-adic Expansion Polygon Triangulations QR Encoder Quadratic Formula Semiprime Numbers Smooth Numbers Snake Sphenic Numbers Taxicab Numbers Turtle Tutorial # Golfer Points Chars Time Submitted 234th jacekwladzinski 559 127 9ms 5 Oct 2025 242nd gchenfc 555 128 9ms 24 Jan 2022 242nd pyrolitic 🇮🇪 555 128 11ms 5 Apr 2022 242nd Wildst 555 128 11ms 4 Aug 2023 242nd sleepyStick 555 128 9ms 7 Dec 2023 242nd damoose717 555 128 10ms 23 May 2025 247th amollberg 🇸🇪 550 129 10ms 21 Jan 2022 247th jfallon1997 550 129 10ms 18 Aug 2022 247th CameronGBell 550 129 10ms 10 Nov 2022 247th 2011-Chan-Ethan 550 129 17ms 20 Jul 2023 247th inverseLorentz 🇦🇺 550 129 10ms 8 Oct 2023 247th trsav 550 129 16ms 29 Oct 2023 247th aalec 550 129 15ms 24 Apr 2024 247th Europe2048 550 129 9ms 16 Mar 2025 247th pquline 550 129 11ms 23 Apr 2025 256th AkashTandon167 546 130 11ms 18 Jan 2022 256th feherd 546 130 17ms 16 Apr 2022 256th caraar12345 546 130 10ms 27 May 2022 256th ordinary-slim 546 130 10ms 18 Nov 2022 256th bonevbs 546 130 10ms 18 Nov 2022 256th mbittner20 546 130 10ms 27 May 2023 256th resoNathan 546 130 9ms 13 May 2024 256th codingisgreatbutiamnot 546 130 11ms 9 Aug 2024 256th NanduBC 546 130 9ms 3 Sep 2024 265th michelebastione 🇮🇹 542 131 17ms 14 Jan 2022 265th midnattssol 🇸🇪 542 131 10ms 19 May 2022 265th aksyristos 542 131 15ms 11 Jun 2023 265th alexjurkiewicz 🇦🇺 542 131 10ms 8 Nov 2023 265th sciencedjinn 542 131 10ms 8 Nov 2024 265th wobblybits 542 131 16ms 15 Aug 2025 265th cthierfelder 🇲🇨 542 131 10ms 12 Sep 2025 265th kayaulai 542 131 10ms 25 days ago 273rd twocatsinatrenchcoat 538 132 9ms 10 May 2022 273rd dillon-duncando 538 132 10ms 19 Oct 2022 273rd eiburns 538 132 11ms 11 Oct 2023 273rd estomagordo 🇳🇱 538 132 9ms 25 Mar 2025 277th adoxography 534 133 10ms 20 Jan 2022 277th jhpaques 🇫🇷 534 133 9ms 26 Jul 2022 277th dranjohn 534 133 10ms 10 Sep 2023 277th countlpaul-dotcom 534 133 16ms 19 Oct 2025 281st zoemarschner 530 134 10ms 16 May 2022 281st nullie 530 134 10ms 8 Jun 2022 281st thomasklunker 530 134 9ms 20 Feb 2023 281st yuchuehw 530 134 10ms 22 Jan 2024 285th petroselo 526 135 10ms 9 Apr 2022 285th trist224 🇫🇷 526 135 10ms 29 Sep 2022 285th mrmena 🇦🇺 526 135 18ms 16 Apr 2024 288th kyleclaassen 522 136 9ms 9 Feb 2022 288th za3k 522 136 10ms 8 Oct 2022 288th shibacho 🇯🇵 522 136 10ms 30 Nov 2022 288th chlorobenzene12 522 136 10ms 26 Dec 2022 288th Schreipfelerer 522 136 10ms 11 Sep 2024 288th hamilton-bonds 522 136 10ms 12 Nov 2024 288th ffelixm 522 136 9ms 7 Jun 2025 295th MathieuIko 518 137 10ms 21 Feb 2022 295th RDShah 518 137 11ms 18 May 2022 295th cameronezell 518 137 10ms 19 Jul 2022 295th enbyte 518 137 16ms 20 Dec 2022 299th Troon 514 138 15ms 11 Oct 2022 299th nayakrujul 514 138 16ms 3 Jan 2023 299th celiendonze 🇨🇭 514 138 10ms 20 Apr 2023 299th willdaspit 514 138 9ms 6 Aug 2023 299th GitQuick 514 138 10ms 9 Mar 2024 304th brochmann 🇸🇪 511 139 9ms 6 Feb 2022 304th halp1 511 139 9ms 8 Apr 2022 304th AliceFord 511 139 10ms 2 Jun 2022 304th luftj 511 139 10ms 9 Aug 2022 304th pustovalovm 511 139 10ms 16 Jan 2023 309th nmgetahun 507 140 10ms 5 Dec 2022 310th LeeCamp 504 141 10ms 12 Jan 2023 310th drochom 504 141 16ms 22 Jun 2024 312th bsoyka 🇺🇸 500 142 10ms 16 Jul 2022 312th ComputerKWasTaken 🇺🇸 500 142 10ms 21 Jan 2025 314th zt14427 497 143 10ms 6 Oct 2023 314th AtengChen 497 143 15ms 7 Sep 2024 316th SniperSmiley 🇺🇸 493 144 9ms 26 Jun 2022 316th rustykitty 🇺🇸 493 144 16ms 28 Oct 2025 318th try-except-try-accept 🇹🇭 490 145 10ms 27 Jun 2022 318th Vaekor 490 145 10ms 9 Jul 2023 320th ThatAlo 486 146 10ms 17 May 2023 First Prev 241–320 of 364 Next Last
