Task: Program Execution
Input (English): 15, 15, ['3521', 'o', 'O', '8905', 's', 'j', 'c', 'U', '5399', 'y', 'F', 'z', 'L', 'W', 'U', '4019', 'a', 'M', 'z', '3219', '6757', 'i']
Output (English): U