Task: Program Execution
Input (English): 20, 21, ['7947', '5731', 'n', '6733', '8693', '5613', 'c', 'C', 'o', '7789', 'B', '3291', 'm', '8909', 'm', '759', '8985', 'v', '9271', '4091', 'N']
Output (English): 4091