Task: Program Execution
Input (English): 9, U, 8, 7, 9, r
Output (English): [['9', 'U', '8', '7', '9'], ['9', 'U', '8', '7', 'r'], ['9', 'U', '8', '9', 'r'], ['9', 'U', '7', '9', 'r'], ['9', '8', '7', '9', 'r'], ['U', '8', '7', '9', 'r']]