Task: Program Execution
Input (English): f, 5, E, 5, r, 1
Output (English): [['f', '5', 'E', '5', 'r'], ['f', '5', 'E', '5', '1'], ['f', '5', 'E', 'r', '1'], ['f', '5', '5', 'r', '1'], ['f', 'E', '5', 'r', '1'], ['5', 'E', '5', 'r', '1']]