Task: Program Execution
Input (English): S, 5, 2, x, 8, 5
Output (English): [['S', '5', '2', 'x', '8'], ['S', '5', '2', 'x', '5'], ['S', '5', '2', '8', '5'], ['S', '5', 'x', '8', '5'], ['S', '2', 'x', '8', '5'], ['5', '2', 'x', '8', '5']]