#include <bits/stdc++.h>
using namespace std;
int n,m,x[55];
vector<pair<int,int>> v[55];
long long dp[1<<20];
bool dfs1(int a,int b,int c,int d){
	if (a==c)
		return 1;
	for (auto& i : v[a])
		if (i.first!=b && dfs1(i.first,a,c,d)){
			x[i.second]^=1<<d;
			return 1;
		}
	return 0;
}
int main(){
	scanf("%d",&n);
	for (int i=1;i<n;i++){
		int ta,tb;
		scanf("%d%d",&ta,&tb);
		v[ta].emplace_back(tb,i);
		v[tb].emplace_back(ta,i);
	}
	scanf("%d",&m);
	for (int i=0;i<m;i++){
		int ta,tb;
		scanf("%d%d",&ta,&tb);
		dfs1(ta,0,tb,i);
	}
	dp[0]=1;
	for (int i=1;i<n;i++)
		for (int j=(1<<m)-1;j>=0;j--)
			dp[j|x[i]]+=dp[j];
	printf("%lld\n",dp[(1<<m)-1]);
}