100 Years Sudoku with 100 year's worth of puzzles! -Num of puzzles Everyday, you get a easy puzzle and a hard one. You can solve not only today's puzzle but also past day's puzzle. You can go back to 1950/1/1. So,there is many many puzzles. -Difficulty There are two kinds of difficulty. Easy or Hard. -Input buttons Number buttons. "∀" button for all inputs. "?" button for a temporary mark. "X" button to delete. "<" and ">" buttons to move. You can solve puzzles comfortably. -Accomplishment d