Task: Program Execution
Input (English): 16, 17, ['R', '2693', '3101', '5143', '2667', '5681', '6991', 'U', '623', 'J', '1815', 'l', 'l', 'Y', '3521', 'D', '5531', '6353', 'e', '6949', 'f', '6853', 'B']
Output (English): D5531