This problem is in Contest(s) below:
Contest 2500:【宏帆初2027级19班】半期测试
Contest 2501:【宏帆初2027级20班】半期测试
Contest 2502:【宏帆初2027级13班】半期测试
Contest 2503:【宏帆初2027级14班】半期测试
Contest 2513:【宏帆初2027级14班】半期测试补题