As we are currently experiencing an overwhelming number of web requests for fetching user submissions, we have temporarily disabled the full submissions list. You must now be logged in to view submissions.
这里有一棵树，具体的，这是一张有 $n$ 个节点和 $n-1$ 条边组成的无向联通图。
每个节点初始颜色为白色，你需要恰好将其中 $k$ 个节点染成黑色，定义一条边的权值是，断开这条边之后，两个连通块的黑色节点个数之差，定义一棵树的权值为所有边的权值求和，你需要最小化整棵树的权值。
第一行两个正整数 $n,k$（$1\leq k\leq n\leq 5\times10^5$）。
接下来 $n-1$ 行，每行两个正整数 $x,y$ 表示树上的一条边。
输出共 $1$ 行，表示最优的染色方案下，这棵树的权值的最小值。
10 4
1 2
2 3
2 4
3 5
3 6
3 7
4 10
6 8
8 916下图展示了一种满足条件的染色方案，边上的数字表示边权。
The discussion section is only for posting: Editorials, General Discussions (problem-solving strategies, alternative approaches), and Off-topic conversations.
This is NOT for reporting issues! If you want to report bugs or errors, please use the Issues section below.
If you find any issues with the problem (statement, scoring, time/memory limits, test cases, etc.), you may submit an issue here. A problem moderator will review your issue.
Guidelines: