a silly little thing i made while messing around.
Rules: Place a number into some cells so that all cells with numbers form one orthogonally connected area. Numbers represent how many of the (up to) four orthogonally adjacent cells contain numbers. No two orthogonally adjacent cells may contain the same number.
Variant: Givens have been replaced with letters. All instances of a letter are the same digit. Different letters may not be the same digit.
