Task: Program Execution
Input (English): 17, 21, ['S', '3913', '2559', '5721', 'J', 'z', 'I', '6355', '6735', '6503', '6241', 'q', 'p', 'o', 'q', 'b', 'x', '61', 'z', 'b', '7849']
Output (English): 7849bz61x