A 3-foot tall monkey problem

A 3-foot tall monkey is in a room where some bananas are suspended from the 8-foot ceiling. He would like to get the bananas. The room contains two stackable, movable, climbable 3-foothigh crates.

Initial state: As described (monkey, bananas suspended from ceiling, 2 crates on the floor in a room)

Goal state: Monkey has bananas.

Successor function: Hop on crate, hop off crate, move/push crate, place crate on top of a stack of crates, walk from a spot to another spot, grab bananas.

Cost function: Number of actions.