This problem is in Contest(s) below:
Contest 1616:NJ24春季信息学奥赛-9
Contest 1550:NJ23秋季信息学奥赛基础-13
Contest 1551:NJ23秋季信息学奥赛提高-12
Contest 1703:25寒假信奥提高1
Contest 1747:25春季信奥编程入门27
Contest 1698:24秋季信奥提高7