Task: Program Execution
Input (English): 1, 2, 9, Y, f, 7, f
Output (English): [['1', '2', '9', 'Y', 'f', '7'], ['1', '2', '9', 'Y', 'f', 'f'], ['1', '2', '9', 'Y', '7', 'f'], ['1', '2', '9', 'f', '7', 'f'], ['1', '2', 'Y', 'f', '7', 'f'], ['1', '9', 'Y', 'f', '7', 'f'], ['2', '9', 'Y', 'f', '7', 'f']]