Task: Program Execution
Input (English): 3, a, 7, 4, N, 1, D
Output (English): [['3', 'a', '7', '4', 'N', '1'], ['3', 'a', '7', '4', 'N', 'D'], ['3', 'a', '7', '4', '1', 'D'], ['3', 'a', '7', 'N', '1', 'D'], ['3', 'a', '4', 'N', '1', 'D'], ['3', '7', '4', 'N', '1', 'D'], ['a', '7', '4', 'N', '1', 'D']]