Find an admissible non-trivial heuristic (i.e. not h(n) = 0, or something similarly trivial) for the problems below. For all of the problems, assume you are using an incremental problem description.

Finding a solution to Sokoban (see link below). The goal is to move crates onto designated squares where you can only move crates when next to them and you can only push them forwards (i.e. you and the crate must move in the same direction and you will end up where the crate was before moving). The goal is to solve the puzzle in as few moves as possible. https://en.wikipedia.org/wiki/Sokoban