Task: Program Execution
Input (English): 18, 21, ['9581', 'Q', 'w', '8565', 'Y', '2921', '9831', '4909', '6577', '7197', 'w', '3981', 's', '8567', 'z', '6009', '1637', 'Z', '6141', '5837', '6517']
Output (English): 651758376141Z