//不怕别人比你聪明，就怕别人比你聪明还比你努力
#include<iostream>
#include<string>
#include<algorithm>
#include<cstdio>
#include<cstring>
#include<cmath>
#include <set>
#include <stack>
#include <map>
#include<vector>
#define INF 0x3f3f3f3fusing namespace std;
const int MAXN = 10005;
vector<int> vec[MAXN];
bool vis[MAXN];
int per[MAXN],head[MAXN],in_num[MAXN];
//in_num统计每个点的入度，为了求根节点，per和并查集中的作用相同，head配合结构体前向星
int cnt,n,m;
//感觉Node
struct Node
{int c,next;
}edge[MAXN];void Init()
{cnt = 0;memset(in_num,0,sizeof(in_num));memset(head,-1,sizeof(head));memset(vis,0,sizeof(vis));for(int i =1;i <= n;i++){vec[i].clear();per[i] = i;}
}void add(int x,int y)
{edge[++cnt].next = head[x];edge[cnt].c = y;head[x] = cnt;
}int Find(int x)
{if(per[x] != x)per[x] = Find(per[x]);return per[x];
}void Union(int x,int y)
{x = Find(x);y = Find(y);if(x == y)return ;per[x] = y;
}void Tarjan(int x)
{for(int i = head[x];i != -1; i =edge[i].next){int v = edge[i].c;Tarjan(v);Union(v,x);//首先要一直遍历的叶子节点
    }vis[x] = 1; // 当这个节点的所有子节点都已经遍历到了，就标记这个节点for(int i = 0;i < vec[x].size();i ++)if(vis[vec[x][i]])//然后在问题中寻找是否有关于这两个节点都已经标记过的了printf("%d 和 %d 的LAC是 %d\n",x,vec[x][i],Find(vec[x][i]));
}
int main()
{int x,y;scanf("%d%d",&n,&m);Init();for(int i = 1;i < n;i++){scanf("%d%d",&x,&y);add(x,y);in_num[y] ++;}for(int i = 0;i < m;i ++){scanf("%d%d",&x,&y);vec[x].push_back(y);vec[y].push_back(x);}int root;for(int i = 1;i <= n;i ++)if(in_num[i] == 0)root = i;Tarjan(root);
}
/**
8 4
1 2
1 3
2 4
2 5
4 7
5 8
3 6
7 8
5 6
5 2
4 6
**/