Task: Program Execution
Input (English): 15, 21, ['u', 's', 'C', '5573', '3229', 'L', 'b', 'S', '1389', 'I', '2193', '9763', '6969', 'B', 'b', '737', '4725', '8581', '3141', 'a', '1757', '147']
Output (English): b, 737, 4725, 8581, 3141, a, 1757