Starting state: there are 2 stacks: - Stack 1: blue block, yellow block, from bottom to top - Stack 2: green block, orange block, purple block, from bottom to top Ending state: there are 5 stacks: - Stack 1: orange block (alone) - Stack 2: purple block (alone) - Stack 3: blue block (alone) - Stack 4: green block (alone) - Stack 5: yellow block (alone)