This problem is in Contest(s) below:
Contest 1349:2024暑期135晚c2
Contest 1351:2024暑期246晚c2
Contest 1400:2025春周五晚c1
Contest 1193:2022秋国庆集训
Contest 1202:c++新生(刷题)
Contest 1276:2023秋季c++c4
Contest 1282:2023秋季c++c3
Contest 1294:2023秋周日晚C4
Contest 1403:2025春周六下c1
Contest 1346:2024暑期新生c++(快班)
Contest 1401:2025春周六早c1
Contest 1375:2024秋季c++周日早c2(塘下)
Contest 1208:2023春季周六早c++五期
Contest 1247:2023暑期C++246晚新生
Contest 1244:2023暑期C++246早新生