Task: Program Execution
Input (English): 2, 7, 5, n, 4, 2
Output (English): [['2', '7', '5', 'n', '4'], ['2', '7', '5', 'n', '2'], ['2', '7', '5', '4', '2'], ['2', '7', 'n', '4', '2'], ['2', '5', 'n', '4', '2'], ['7', '5', 'n', '4', '2']]