Task: Program Execution
Input (English): 4, ['1939', '4549', 'U', 'q', '8453', '7847', 'w', 'P', '9573', '5409', 'd', 'T', '9511', '3879', '8793', 'K', '3971', '75', 'O']
Output (English): 1939, 8453, 9573, 9511, 3971