Task: Program Execution
Input (English): U, 7, 6, 9, C, 4
Output (English): [['U', '7', '6', '9', 'C'], ['U', '7', '6', '9', '4'], ['U', '7', '6', 'C', '4'], ['U', '7', '9', 'C', '4'], ['U', '6', '9', 'C', '4'], ['7', '6', '9', 'C', '4']]