The Calendar hole will go live in approximately 4 days. Why not try and solve it ahead of time?
Reverse Polish Notation in all languages 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 801st inventshah 551 122 2,842ms 7 Nov 2022 802nd iczelia 🇩🇪 550 212 1ms 11 Oct 2025 803rd keelimeguy 🇺🇸 550 255 2,403ms 5 Nov 2023 803rd yeminghan2021 550 255 65ms 2 Feb 2025 805th GolfingSuccess 🇬🇷 549 114 2ms 16 Oct 2024 806th KatieLG 🇬🇧 548 74 5ms 19 Mar 2022 807th nstearns96 🇬🇧 548 137 24ms 15 Dec 2022 807th mossprescott 548 137 11ms 19 Jan 2023 807th taesungh 548 137 16ms 15 Oct 2023 807th PyryL 🇫🇮 548 137 18ms 25 Aug 2024 811th stellartux 547 123 380ms 24 Dec 2023 812th zakariamouhid 547 134 10ms 11 May 2023 813th michelebastione 🇮🇹 544 138 16ms 19 Feb 2022 813th knutae 🇳🇴 544 138 15ms 8 Mar 2022 813th RDShah 544 138 32ms 15 May 2022 813th ImpressedByRocks 544 138 16ms 10 Oct 2024 817th c0d3-4-F00d 🇩🇪 544 214 2ms 24 Feb 2022 818th codewrite 🇬🇧 542 252 374ms 13 May 2025 819th MeWhenI 🇻🇦 540 64 2ms 15 Feb 2022 820th Shanethegamer 🇺🇸 540 116 2ms 5 Nov 2022 821st cefqrn 540 139 17ms 20 Dec 2022 821st alfonsoalves 540 139 17ms 1 Mar 2024 821st hiichbindermax 540 139 37ms 19 Sep 2024 821st jacekwladzinski 540 139 11ms 10 Oct 2025 825th m-tkach 🇺🇦 539 74 39ms 25 Jun 2024 826th hjcafaroUC 539 260 2,434ms 20 Aug 2022 827th bac0id 537 217 1ms 27 Jun 2024 828th snoozingnewt 🇨🇦 534 253 107ms 8 Oct 2025 829th MeWhenI 🇻🇦 533 76 5ms 16 Apr 2023 830th SirFireball3521 533 141 37ms 7 Feb 2023 830th AstroOrbis 533 141 15ms 12 Jul 2025 830th RaBa21 🇭🇺 533 141 10ms 14 Jul 2025 833rd MeWhenI 🇻🇦 533 208 99ms 16 Oct 2022 834th neel11235813 531 125 434ms 17 Mar 2024 835th IlkkaTakala 531 264 2,567ms 20 Dec 2023 836th KatieLG 🇬🇧 531 470 1,882ms 21 Nov 2025 837th codewrite 🇬🇧 530 345 266ms 16 Jun 2025 838th MichalMarsalek 🇨🇿 529 142 15ms 14 Feb 2022 838th marcin7Cd 529 142 15ms 20 Feb 2022 840th MeWhenI 🇻🇦 528 317 32ms 6 Jun 2023 841st varhammer 🇷🇺 526 196 5ms 13 Dec 2023 842nd janbehrens 🇩🇪 525 128 1,867ms 23 Feb 2022 843rd SniperSmiley 🇺🇸 525 143 15ms 8 Jul 2022 843rd Europe2048 525 143 24ms 22 Oct 2024 843rd moustave 525 143 11ms 7 Apr 2025 846th MeWhenI 🇻🇦 523 139 787ms 15 Sep 2025 847th randolchance 522 144 20ms 4 Jan 2024 847th roupiq 🇵🇱 522 144 17ms 1 Mar 2024 847th robin-scragg 522 144 18ms 22 Aug 2025 847th Deppyforce 522 144 15ms 9 Nov 2025 851st warmCabin 522 223 2ms 15 Apr 2022 852nd Shanethegamer 🇺🇸 520 224 2ms 28 May 2025 853rd MeWhenI 🇻🇦 520 246 363ms 27 Jul 2024 854th postie77 520 263 336ms 19 May 2023 855th MeWhenI 🇻🇦 519 255 150ms 13 Feb 2022 856th ovs-code 🇩🇪 519 398 9ms 8 Jul 2024 857th DialFrost 🇸🇬 518 77 40ms 25 Dec 2024 858th LeeCamp 518 145 16ms 14 Feb 2022 858th hellwue 518 145 10ms 7 Feb 2023 858th adamnielson42 🇺🇸 518 145 25ms 8 Oct 2024 858th Mabeloid 🇳🇴 518 145 26ms 4 May 2025 858th te-chnical 518 145 16ms 9 Jul 2025 863rd karhuthebear 515 146 16ms 6 May 2022 863rd Bonjour27891 🇻🇳 515 146 11ms 17 Jul 2022 863rd Player01osu 515 146 11ms 28 Oct 2023 866th nephila-nacrea 🇬🇧 513 79 5ms 20 Feb 2022 867th error256 511 51 3ms 6 May 2024 868th Bodo171 511 147 19ms 7 Dec 2022 868th vgamula 🇺🇦 511 147 15ms 6 Nov 2023 868th croc54 511 147 15ms 27 Jan 2025 871st Sciman101 511 192 2ms 27 Mar 2025 872nd MeWhenI 🇻🇦 509 367 202ms 15 Feb 2022 873rd davecame 508 148 26ms 18 Sep 2023 874th dokutan 508 193 2ms 13 Jan 2025 875th Yewzir 🇧🇪 505 63 69ms 11 Mar 2024 876th rucin93 🇵🇱 505 79 45ms 31 May 2025 877th namcartoon06 504 278 2,510ms 30 Jun 2023 878th HumanoidCPU 503 132 372ms 29 Sep 2024 879th MeWhenI 🇻🇦 503 370 28ms 14 Feb 2022 880th adamnielson42 🇺🇸 502 146 9ms 2 Jun 2023 First Prev 801–880 of 1,156 Next Last