Task: Program Execution
Input (English): 15, 21, ['2279', '3249', 'u', '7055', 'Q', '111', '5711', 'p', 'Q', '6269', 'Q', '2791', 'O', 'q', '6293', 'U', '7887', 'P', '2521', 'd', 'X', '4215', 'J', 'I', '7703']
Output (English): Xd2521P7887U6293