Task: Program Execution
Input (English): 4, 7, ['5365', '2617', 'U', 'c', 'b', '1891', 'I', 'e', '9921', 'x', '7833', 'v', 'z', 'w', 'T', 'K', '7647', 'l', 'J']
Output (English): I1891bc