Task: Program Execution
Input (English): 21, 21, ['4197', 'Q', '5743', 'x', '1657', '5973', '7317', 'H', 'L', 'x', '3295', '7461', '5887', 'o', 'M', 'x', '7071', '2507', 's', 'P', 'y', '1389', '6039', 'k']
Output (English): y