#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<algorithm>
#include<cctype>
#include<cmath>
#include<cstdlib>
#include<queue>
#include<ctime>
#include<vector>
#include<set>
#include<map>
#include<stack>
using namespace std;
const int LOG = 20;
vector<int>v[100010];
int ans,id[100010],col[440000],n,m;
int son[100010],siz[100010],cnt,dep[100010],fa[100010],acc[100010];
inline void dfs(int x,int la){int maxn=0;siz[x]=1;for(int i=0;i<v[x].size();i++)if(v[x][i]!=la){fa[v[x][i]]=x;dep[v[x][i]]=dep[x]+1;dfs(v[x][i],x);siz[x]+=siz[v[x][i]];if(siz[v[x][i]]>maxn){maxn=siz[v[x][i]];son[x]=v[x][i];}}return;
}
inline void dfs2(int x,int ac){id[x]=++cnt;acc[x]=ac;if(!son[x])return;dfs2(son[x],ac);for(int i=0;i<v[x].size();i++)if(v[x][i]!=fa[x]&&v[x][i]!=son[x])dfs2(v[x][i],v[x][i]);return;
}
inline void update(int le,int ri,int wh,int x,int y,int k){if(x>y)return;if(le>=x&&ri<=y){col[wh]+=k;return;}int mid=(le+ri)>>1;if(col[wh]){col[wh<<1]+=col[wh];col[wh<<1|1]+=col[wh];col[wh]=0;}if(mid>=x)update(le,mid,wh<<1,x,y,k);if(mid<y)update(mid+1,ri,wh<<1|1,x,y,k);return;
}
inline int q(int le,int ri,int wh,int pl){if(le==ri)return col[wh];int mid=(le+ri)>>1,ans;if(col[wh]){col[wh<<1]+=col[wh];col[wh<<1|1]+=col[wh];col[wh]=0;}if(mid>=pl)ans=q(le,mid,wh<<1,pl);else ans=q(mid+1,ri,wh<<1|1,pl);return ans;
}
inline void solve(int x,int y){while(acc[x]!=acc[y]){if(dep[acc[x]]<dep[acc[y]])swap(x,y);update(1,n,1,id[acc[x]],id[x],1);x=fa[acc[x]];}if(id[x]>id[y])swap(x,y);update(1,n,1,id[x]+1,id[y],1);return;
}
int main(){int i,j,k;scanf("%d%d",&n,&m);for(i=1;i<n;i++){int x,y;scanf("%d%d",&x,&y);v[x].push_back(y);v[y].push_back(x);}fa[1]=0,dep[1]=1;dfs(1,0);dfs2(1,1);for(i=1;i<=m;i++){int x,y;scanf("%d%d",&x,&y);solve(x,y);}for(i=2;i<=n;i++){int x=q(1,n,1,id[i]);if(x==0)ans+=m;else if(x==1)ans+=1;}printf("%d\n",ans);return 0;
}