This problem is in Contest(s) below:
Contest 1391:周日早for循环(塘下)
Contest 1346:2024暑期新生c++(快班)
Contest 1379:2024秋周日晚c1
Contest 1370:2024秋周六下c1
Contest 1212:2023春周六下c++一期
Contest 1377:2024秋季c++周日下c1(塘下)
Contest 1218:2023春周日早c++一期