Task: Program Execution
Input (English): 18, 21, ['N', 'b', 'K', 'U', 'Y', '3503', '9659', '4535', 'H', '9331', 'P', '115', '9071', 'H', 'Z', 'L', '1619', 'C', 'u', 'r', '8757', 'R', 'y']
Output (English): 8757ruC