#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define mod 1000000007
#define lim 1000000000000000007
#define lim1 18446744073709551615  //Unsigned
#define sq(a) ((a)*(a))
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define mms(v,i) memset(v,i,sizeof(v))
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define REP(i,a,b) for (int i = a; i <= b; i++)
#define REPN(i,a,b) for (int i = a; i >= b; i--)
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;
typedef pair<int,int> pi;
typedef pair<ll,ll> PL;
typedef pair<ll,int> PLI;
typedef pair<int,ll> PIL;
typedef pair<int,pair<int,int> > pii;
typedef pair<double,double> pdd;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> indexed_set;
ll power(ll a,ll b) {
    if (b==0) return 1;
    ll c = power(a,b>>1);
    c = (c*c)%mod;
    if (b&1) return (c*a)%mod;
    return c;
}
ll gcdll(ll a,ll b) {
    if (b==0) return a;
    return gcdll(b,a%b);
}
int gcd(int a,int b) {
    if (b==0) return a;
    return gcd(b,a%b);
}

struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

const int N = (int)3e5+5;
const int Q = 301;

int dist[55][55];
vector<pi> edges, conditions;
vector<int> v[55];
void dfs(int n,int i,int p,int d) {
    dist[n][i] = d;
    for (auto it:v[i]) {
        if (it!=p){
            dfs(n,it,i,d+1);
        }
    }
}
bool check(int i, int k) {
    int a = edges[i].first;
    int b = edges[i].second;
    int u = conditions[k].first;
    int v = conditions[k].second;
    if (dist[a][u]+1+dist[b][v] == dist[u][v]) {
        return true;
    }
    if (dist[a][v]+1+dist[b][u] == dist[u][v]) {
        return true;
    }
    return false;
}
ll dp[55][1<<20];
ll rec(int i,int n,int m,int rem) {
    if (i==n-1) {
        return (rem==0);
    }
    if (dp[i][rem] != -1) return dp[i][rem];
    //Select i'th edge
    int temp = rem;
    ll ret = 0;
    REP(k,0,m-1) {
        if ((1<<k)&rem && check(i,k)) {
            temp -= (1<<k);
        }
    }
    ret += rec(i+1,n,m,temp);
    //Don't select i'th edge
    ret += rec(i+1,n,m,rem);
    dp[i][rem] = ret;
    return ret;
}
void solve() {
    mms(dp,-1);
    int n,a,b;
    cin>>n;
    REP(i,1,n-1) {
        cin>>a>>b;
        v[a].pb(b);
        v[b].pb(a);
        edges.pb({a,b});
    }
    REP(i,1,n) {
        dfs(i,i,i,0);
    }
    int m;
    cin>>m;
    REP(i,1,m) {
        cin>>a>>b;
        conditions.pb({a,b});
    }
    cout<<rec(0,n,m,(1<<m)-1);
}
int main() {
    //freopen("output.txt","r",stdin);
    //freopen("output.txt","w",stdout);

    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int T=1;
    //cin>>T;
    REP(TC,1,T) {
        //cout<<"Case #"<<TC<<": ";
        solve();
        //cout<<"\n";
    }
}


Measured memory_bytes: 450816