Task: Program Execution
Input (English): 18, 21, ['7731', '6997', '6801', '9517', 'C', '1231', 'h', 'e', '121', '4987', '8961', 'j', 'y', 'A', 't', 'e', '3331', 'F', 'S', '8907', '1557', 'a', '2851', 'v', '6725', '3607', 'M', '4235']
Output (English): 15578907SF