#include <bits/stdc++.h>
using namespace std;
 
#define pb push_back
#define ll long long
#define bit(n, i) ((n >> i) & 1)
#define all(a) a.begin(), a.end()
#define rep(i, x, n) for (int i = x; i <= n; ++i)
#define red(i, x, n) for (int i = x; i >= n; --i)
#define inp(a) freopen(a".inp", "r", stdin), freopen(a".out", "w", stdout)
 
template<class A, class B> inline void maximize(A &x, B y) {x = max(x, y);};
template<class A, class B> inline void minimize(A &x, B y) {x = min(x, y);};
 
const int N = 1e3 + 5;
const int M = 2e5 + 5;
const ll MOD = 1e9 + 7;
 
 
int n;
vector<int> a[M];
 
bool d[M];
 
void BFS(int A, int B){
    queue<int> q;
    vector<int> trace(n + 1, 0);
 
    d[A] = 1; q.push(A);
    trace[A] = -1;
 
    while (q.size()){
        int u = q.front(); q.pop();
 
        for (int v: a[u]) if (trace[v] == 0){
            trace[v] = u;
 
            if (v == B) break;
 
            q.push(v);
        }
    }
 
    while (B != A){
        d[B] = 1; B = trace[B];
    }
}
int main(){
    cin.tie(0) -> sync_with_stdio(0);
 
    cin >>n;
 
    rep(i, 2, n){
        int u, v; cin >>u >>v;
 
        a[u].pb(v); a[v].pb(u);
    }
 
    int q; cin >>q;
 
    while (q--){
        int A, B; cin >>A >>B;
 
        BFS(A, B);
    }
 
    int cnt = 0;
    rep(u, 1, n) if (d[u] == 0) ++cnt;
 
    cout <<cnt;
 
    return 0;
}
 

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