//郑老师和na姐一样可爱^ ^
#include <bits/stdc++.h>
using namespace std;
const int N = 1e6+10;
const int M = 998244353;
const int mod = 998244353;
#define int long long
int up(int a,int b){return a<0?a/b:(a+b-1)/b;}
#define endl '\n'
#define all(x) (x).begin(),(x).end()
#define YES cout<<"YES"<<endl;
#define NO cout<<"NO"<<endl;
#define _ 0
#define db double
#define pi acos(-1)
#define INF 0x3f3f3f3f3f3f3f3f
#define PII pair<int,int>
#define fast ios::sync_with_stdio(false);cin.tie(nullptr);
vector<int>g[500010];
int n,m,depth[500010],fa[500010][21],dp[500010],ans;
void bfs(int x){
    memset(depth,0x3f3f,sizeof depth);
    queue<int>q;q.push(x);
    depth[0]=0,depth[x]=1;
    while(q.size()){
        auto u=q.front();q.pop();
        for(auto v:g[u]){
            if(depth[v]>depth[u]+1){
                depth[v]=depth[u]+1;
                q.push(v);
                fa[v][0]=u;
                for(int k=1;k<=19;k++)fa[v][k]=fa[fa[v][k-1]][k-1];
            }
        }
    }
}
int lca(int a,int b){
    if(depth[a]>depth[b])swap(a,b);
    for(int k=19;k>=0;k--)if(depth[fa[b][k]]>=depth[a])b=fa[b][k];
    if(a==b)return a;
    for(int k=19;k>=0;k--){
        if(fa[a][k]!=fa[b][k]){
            a=fa[a][k];
            b=fa[b][k];
        }
    }
    return fa[a][0];
}
int dis(int a, int b){
    int c = lca(a, b);
    return abs(depth[c]-depth[a]) + abs(depth[c]-depth[b]);
}
void dfs(int u){
    for(auto v:g[u]){
        if(depth[v]<depth[u])continue;
        dfs(v);
        dp[u]+=dp[v];
        if(!dp[v])ans+=m;
        else if(dp[v]==1)ans++;
    }
}
void solve(){
    cin>>n>>m;
    for(int i=1;i<n;i++){
        int u,v;cin>>u>>v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    bfs(1);
    for(int i=0;i<m;i++){
        int u,v;cin>>u>>v;
        int f=lca(u,v);
        dp[f]-=2;
        dp[u]++,dp[v]++;
    }
    dfs(1);
    cout<<ans<<endl;
}
signed main(){
    fast
    int t;t=1;//cin>>t；
    while(t--) {
        solve();
    }
    return ~~(0^_^0);
}
//注意代码要放在两组三个点之间，才可以正确显示代码高亮哦~