Task: Program Execution
Input (English): 1, 3, ['X', '3077', '4121', 'S', '4525', '7861', '6013', '5883', '7819', '9867', '3777', '8957', 'f', '2351', 'C', 'x', '2557', 'P', '8949', 'p', 'W', 'n']
Output (English): 4121, 3077, X