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 158th Attero 🇸🇪 612 116 9ms 2 Jan 2024 158th RobertHoeh 612 116 10ms 9 Apr 2024 158th Mabeloid 🇳🇴 612 116 9ms 7 Oct 2024 158th rollershutter 612 116 9ms 24 Feb 2025 165th CedricGebistorf 607 117 10ms 19 Feb 2022 165th FranklinJiaChen 607 117 10ms 10 Aug 2024 167th hiichbindermax 602 118 9ms 26 Feb 2022 167th Tess2662 602 118 10ms 8 Sep 2022 167th randolchance 602 118 9ms 20 Mar 2023 167th gabe-gallegos 602 118 9ms 19 May 2024 167th martion2007 602 118 10ms 14 Aug 2024 167th orifu 602 118 9ms 4 Nov 2024 167th TheZwierzLF 🇵🇱 602 118 10ms 27 May 2025 167th addmai 602 118 9ms 30 Jul 2025 175th RYNO8 597 119 9ms 18 Feb 2022 175th eshilo-draper 597 119 11ms 10 Oct 2022 175th georgehulme 597 119 10ms 12 Oct 2022 175th Omega65536 🇩🇪 597 119 11ms 24 Nov 2022 175th Ripick 597 119 10ms 2 Feb 2023 175th Ythaenagor 597 119 10ms 5 Aug 2024 175th PyryL 🇫🇮 597 119 10ms 20 Aug 2024 175th Stockoh 🇫🇷 597 119 9ms 13 Feb 2025 175th Alban-Boissard 597 119 10ms 14 Jun 2025 184th fkantelberg 592 120 9ms 18 Jul 2023 184th Bmrl7 592 120 9ms 29 Feb 2024 186th Natanaelel 🇸🇪 587 121 9ms 12 Jan 2022 186th NerdyMcNerd42 587 121 9ms 20 Aug 2022 186th Kloppermand 🇩🇰 587 121 10ms 3 Oct 2022 186th ehulinsky 🇺🇸 587 121 16ms 15 May 2023 186th AbhilashaTandon 587 121 10ms 21 Sep 2023 186th davecame 587 121 9ms 2 Oct 2023 186th gussy420 587 121 9ms 23 Oct 2023 186th tobyLovick 587 121 9ms 13 Dec 2023 194th jm600 582 122 9ms 19 Apr 2022 194th krcs 🇵🇱 582 122 10ms 29 Apr 2022 194th bbakersmith 582 122 10ms 6 Jun 2022 194th nstearns96 🇬🇧 582 122 10ms 29 Nov 2022 194th stertooy 🇧🇪 582 122 10ms 11 Jun 2024 194th croc54 582 122 11ms 8 Jan 2025 194th Matter1024 🇮🇳 582 122 9ms 15 Nov 2025 201st andre-lameirinhas 🇵🇹 577 123 9ms 8 Aug 2022 201st MaxElf999 577 123 10ms 13 Sep 2022 201st Mikey-Beep 🇬🇧 577 123 10ms 24 Aug 2023 201st bac0id 577 123 17ms 22 Sep 2023 201st Masttest 577 123 12ms 21 days ago 201st yujqiao 577 123 10ms 2 days ago 207th Ailko 🇧🇪 573 124 11ms 6 May 2022 207th qwjhvbxi 573 124 10ms 10 Feb 2024 207th leon-w 573 124 11ms 24 Jul 2024 207th jbjd 573 124 16ms 12 Sep 2024 207th smilesformiles3 573 124 10ms 14 Jun 2025 212th BenBanerjeeRichards 568 125 10ms 22 Apr 2022 212th richard-oelze 🇩🇪 568 125 9ms 8 May 2022 212th vishwathg 568 125 15ms 16 Sep 2022 212th Thonoton 568 125 16ms 24 Feb 2023 212th sandorstormen 568 125 16ms 11 Mar 2023 212th MiranDaniel 🇨🇿 568 125 16ms 28 Apr 2023 212th VictorStenvers 🇳🇱 568 125 17ms 26 Jun 2024 212th Terobero 568 125 16ms 3 Sep 2024 212th LostSyntax21 🇬🇧 568 125 16ms 9 Sep 2024 212th jamesthekee 568 125 10ms 22 Jan 2025 222nd TobyBoyne 🇬🇧 563 126 11ms 28 Jan 2022 222nd OllieBoyne 🇬🇧 563 126 10ms 2 Mar 2022 222nd Anonymousellama21 563 126 10ms 14 Apr 2022 222nd Trunksistor 🇫🇷 563 126 11ms 19 Apr 2022 222nd docd 563 126 16ms 8 Aug 2022 222nd LogicalJoe 563 126 16ms 4 May 2023 222nd pde-bakk 🇳🇱 563 126 10ms 23 Oct 2023 222nd mstang107 563 126 10ms 20 Dec 2023 222nd DGipe 563 126 9ms 13 May 2024 222nd retrohun 563 126 9ms 18 Oct 2024 222nd yokasuretsu 563 126 9ms 23 Jan 2025 222nd bknower 563 126 10ms 26 Jun 2025 234th jacklynnepenick 559 127 9ms 15 Feb 2022 234th Pena86 559 127 16ms 14 Sep 2022 234th pascscha 559 127 9ms 18 Sep 2022 234th DrPiranoid 559 127 10ms 8 Oct 2022 234th epic-programmer-guy 559 127 10ms 21 Dec 2023 234th 40fied4t 559 127 10ms 15 May 2025 234th Luke44565 559 127 9ms 10 Aug 2025 First Prev 161–240 of 364 Next Last
