Task: Program Execution
Input (English): b, 4, M, x, D
Output (English): [['b', '4', 'M', 'x'], ['b', '4', 'M', 'D'], ['b', '4', 'x', 'D'], ['b', 'M', 'x', 'D'], ['4', 'M', 'x', 'D']]