Task: Program Execution
Input (English): 4, 20, ['H', '4189', '3945', '8339', 'o', '6807', '8955', '8201', 'H', '1803', '9507', '3671', '6573', 'X', 'J', 'x', '8751', '9333', '3955', '9971', '1981']
Output (English): 9971395593338751xJX6573367195071803H820189556807o8339