Task: Program Execution
Input (English): 1, 5, ['3377', '7877', '9527', 'x', 'a', '3697', '4503', '8231', 'w', '8821', '8311', '6397', 'B', '7909', '6897', 'Y', 'G', 'l', '8299', '4717', 'G']
Output (English): ax725977877733