Task: Program Execution
Input (English): b, 7, c, 6, 2, U, 3
Output (English): [['b', '7', 'c', '6', '2', 'U'], ['b', '7', 'c', '6', '2', '3'], ['b', '7', 'c', '6', 'U', '3'], ['b', '7', 'c', '2', 'U', '3'], ['b', '7', '6', '2', 'U', '3'], ['b', 'c', '6', '2', 'U', '3'], ['7', 'c', '6', '2', 'U', '3']]