Found “The Worlds Longest Sudoku Puzzle” someone gave me years back. Starting it now and feel like there may be an error. Am I missing something? Trying to input a 7 into
The Largest Sudoku Book in the History of the Universe - 4000 PUZZLES: easy - medium - hard - extreme | 4 Difficulty Levels | Activity Puzzle Book For Adults: Enigma SDK: 9798649056441: Amazon.com: Books