This problem is in Contest(s) below:
Contest 1164:2022暑期246晚c++第二期
Contest 1298:2023秋周日晚(忠义街)
Contest 1159:2022暑期246早c++第二期
Contest 1350:2024暑期135晚c1
Contest 1160:2022暑期246早c++第二期(平阳)
Contest 1313:2024春周五晚c++c1
Contest 1353:2024暑期246晚p2
Contest 1310:2023寒假下c1
Contest 1400:2025春周五晚c1
Contest 1403:2025春周六下c1
Contest 1401:2025春周六早c1
Contest 1407:2025春周六早c++1(平阳)
Contest 1368:2024秋周六早c1(平阳)