Task: Program Execution
Input (English): 15, 18, ['8311', '9791', 'U', 's', 'U', 'd', '1057', 'v', 'R', 'N', '9469', 'G', 'l', '7209', 'N', 'z', '2139', '7857', 'G', 'z', 'X', '9879', '4113']
Output (English): 75879312zN