This problem is in Contest(s) below:
Contest 1118:ZWL-C++编程入门1
Contest 1189:C++编程入门29
Contest 1259:暑期C++入门集训1
Contest 1288:2022秋季C++入门1
Contest 1766:2025CYX暑期编程训练1
Contest 1767:2025CYX暑期编程训练2
Contest 1018:2020编程实践1-入门实践
Contest 1000:Python编程入门训练1
Contest 1002:编程入门1
Contest 1005:2020新沂一中信息学奥赛集训营0725
Contest 1401:Python程序设计训练2