Task: Program Execution
Input (English): 8, 6, 3, 1, D, 6
Output (English): [['8', '6', '3', '1', 'D'], ['8', '6', '3', '1', '6'], ['8', '6', '3', 'D', '6'], ['8', '6', '1', 'D', '6'], ['8', '3', '1', 'D', '6'], ['6', '3', '1', 'D', '6']]