100 doors runaway level 73 : Take the rope on the floor, then grab the chainsaw in a tree. Cut the tree trunk with a chainsaw. Put the rope on the wheel right next door, and in a fallen tree. Turn the wheel to lift a fallen tree to disappear. View the rest of the tree is still there, you will see the code number 1783.
enter the number 1783 on the keypad, the door will open.