classic Sokoban game

classic Sokoban game: Arrow Keys to Move.Key P previous level,Key N next level. Only one box can be pushed at a time. A box cannot be pulled. The player cannot walk through boxes or walls. The puzzle is solved when all boxes are located at storage locations.so many many levels is waiting for you,the pleasure and challenge is unlimited.there are 4667 levels so far.Now there is answer for 4100 levels in game.