Task: Program Execution
Input (English): 6, ['w', '283', 'x', 'u', 'B', '8661', 'f', '2185', '1701', '6637', '4109', 'x', 'O', 'j', 'k', 'r', 'U', 't', '4287', '5051', 'd', '3599']
Output (English): w, f, O, 4287