Task: Program Execution
Input (English): 18, 18, ['K', 'n', 'x', '7817', 'i', '5455', 'I', '427', 'O', '647', '9451', 'V', '7667', '2203', '4221', '1771', 'y', 'z', 'U', 'T', '2261']
Output (English): z