Task: Program Execution
Input (English): r, u, 6, 5, 4, 0, L
Output (English): [['r', 'u', '6', '5', '4', '0'], ['r', 'u', '6', '5', '4', 'L'], ['r', 'u', '6', '5', '0', 'L'], ['r', 'u', '6', '4', '0', 'L'], ['r', 'u', '5', '4', '0', 'L'], ['r', '6', '5', '4', '0', 'L'], ['u', '6', '5', '4', '0', 'L']]