Task: Program Execution
Input (English): v, d, 4, 7, d, U
Output (English): [['v', 'd', '4', '7', 'd'], ['v', 'd', '4', '7', 'U'], ['v', 'd', '4', 'd', 'U'], ['v', 'd', '7', 'd', 'U'], ['v', '4', '7', 'd', 'U'], ['d', '4', '7', 'd', 'U']]