Task: Program Execution
Input (English): B, 8, 7, 6, 7, b, 5
Output (English): [['B', '8', '7', '6', '7', 'b'], ['B', '8', '7', '6', '7', '5'], ['B', '8', '7', '6', 'b', '5'], ['B', '8', '7', '7', 'b', '5'], ['B', '8', '6', '7', 'b', '5'], ['B', '7', '6', '7', 'b', '5'], ['8', '7', '6', '7', 'b', '5']]