Task: Program Execution
Input (English): 9, 7, 4, U, 2, 4, P
Output (English): [['9', '7', '4', 'U', '2', '4'], ['9', '7', '4', 'U', '2', 'P'], ['9', '7', '4', 'U', '4', 'P'], ['9', '7', '4', '2', '4', 'P'], ['9', '7', 'U', '2', '4', 'P'], ['9', '4', 'U', '2', '4', 'P'], ['7', '4', 'U', '2', '4', 'P']]