Task: Program Execution
Input (English): 5, 21, ['7201', '6357', '2525', 'Z', 'u', 'w', '3349', '4977', 'D', '3617', 'M', '7621', '947', '7525', 'Y', '1617', '145', '807', '3675', '3355', 'a', '1679']
Output (English): uw33494977D3617M76219477525Y161714580736753355a