Task: Program Execution
Input (English): 6, ['6291', 'y', '1231', '1319', '4669', 'D', 'Z', '9019', 'C', '1455', 's', 'u', 'B', 'C', '8669', 'G', '5183', '1947', '7653', 'O']
Output (English): 6291, Z, B, 7653