Task: Program Execution
Input (English): 18, 19, ['f', 'B', 'K', 'X', 'H', 'v', 'e', 'D', 'S', '7497', 'J', '8021', 'Z', '5011', '5765', '6123', 'U', 'e', '3961', 'r', 'z', '5145', '3935', '299', '5457']
Output (English): e3961