  Sumplete is a logic puzzle famous for being developed by ChatGPT. The puzzle
consists of a rectangular grid, with each cell containing a number. The player
has to cross out some numbers such that the sum of uncrossed numbers in each
row and column is equal to a given integer assigned to that row or column. In
this paper, we prove that deciding solvability of a given Sumplete puzzle is
NP-complete, even if the grid contains only two different numbers.
