#include <bits/stdc++.h>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
template<int mod>istream &operator>>(istream &is,static_modint<mod> &a){long long b;is>>b;a=b;return is;}
istream &operator>>(istream &is,modint &a){long long b;cin>>b;a=b;return is;}
#endif
using ll=long long;
using ull=unsigned long long;
using P=pair<ll,ll>;
template<typename T>using minque=priority_queue<T,vector<T>,greater<T>>;
template<typename T>bool chmax(T &a,const T &b){return (a<b?(a=b,true):false);}
template<typename T>bool chmin(T &a,const T &b){return (a>b?(a=b,true):false);}
template<typename T1,typename T2>istream &operator>>(istream &is,pair<T1,T2>&p){is>>p.first>>p.second;return is;}
template<typename T>istream &operator>>(istream &is,vector<T> &a){for(auto &i:a)is>>i;return is;}
template<typename T1,typename T2>void operator++(pair<T1,T2>&a,int n){a.first++,a.second++;}
template<typename T1,typename T2>void operator--(pair<T1,T2>&a,int n){a.first--,a.second--;}
template<typename T>void operator++(vector<T>&a,int n){for(auto &i:a)i++;}
template<typename T>void operator--(vector<T>&a,int n){for(auto &i:a)i--;}
#define reps(i,a,n) for(int i=(a);i<(n);i++)
#define rep(i,n) reps(i,0,n)
#define all(x) x.begin(),x.end()
#define pcnt(x) __builtin_popcount(x)
ll myceil(ll a,ll b){return (a+b-1)/b;}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) static_cast<void>(0)
template<typename T1,typename T2>ostream &operator<<(ostream &os,const pair<T1,T2>&p){os<<p.first<<' '<<p.second;return os;}
#endif
void SOLVE();
int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  #ifdef LOCAL
  clock_t start=clock();
  #endif
  int testcase=1;
  //cin>>testcase;
  for(int i=0;i<testcase;i++){
    SOLVE();
  }
  #ifdef LOCAL
  cout<<"time:";
  cout<<(clock()-start)/1000;
  cout<<"ms\n";
  #endif
}
struct HeavyLightDecomposition{
private:
  int n;
  vector<vector<int>>to;
  int root;
  vector<int>par,pathtop,in,out;
public:
  vector<int>stsize;
private:
  void st_dfs(int x,int p){
    par[x]=p;
    stsize[x]=1;
    for(auto &i:to[x]){
      if(i==p){
        if(i==to[x].back())break;
        else swap(i,to[x].back());
      }
      st_dfs(i,x);
      stsize[x]+=stsize[i];
      if(stsize[i]>stsize[to[x][0]]){
        swap(i,to[x][0]);
      }
    }
  }
  void hld_dfs(int x,int p,int &id){
    in[x]=id++;
    for(auto i:to[x])if(i!=p){
      pathtop[i]=(i==to[x][0]?pathtop[x]:i);
      hld_dfs(i,x,id);
    }
    out[x]=id;
  }
public:
  HeavyLightDecomposition(int n,int root=0):n(n),to(n),stsize(n),par(n),in(n),out(n),root(root),pathtop(n){}
  void add_edge(int u,int v){
    to[u].emplace_back(v);
    to[v].emplace_back(u);
  }
  void build(){
    st_dfs(0,-1);
    pathtop[root]=root;
    int id=0;
    hld_dfs(0,-1,id);
  }
  inline int get(int x)const{return in[x];}
  int lca(int u,int v)const{
    int pu=pathtop[u],pv=pathtop[v];
    while(pathtop[u]!=pathtop[v]){
      if(in[pu]>in[pv])u=par[pu],pu=pathtop[u];
      else v=par[pv],pv=pathtop[v];
    }
    return (in[u]>in[v]?v:u);
  }
  void subtree_query(int u ,const function<void(int,int)> &f){
    f(in[u],out[u]);
  }
  void path_query(int u,int v,const function<void(int,int)>&f){
    int pu=pathtop[u],pv=pathtop[v];
    while(pathtop[u]!=pathtop[v]){
      if(in[u]>in[v])f(in[pu],in[u]+1),u=par[pu],pu=pathtop[u];
      else f(in[pv],in[v]+1),v=par[pv],pv=pathtop[v];
    }
    if(in[u]>in[v])swap(u,v);
    f(in[u],in[v]+1);
  }
};
struct S{
  int sz;
  ll sum;
};
S op(S a,S b){
  return {a.sz+b.sz,a.sum+b.sum};
}
S e(){return {0,0};}
S mapping(ll f,S x){
  if(f==0)return x;
  x.sum+=f*x.sz;
  return x;
}
ll composition(ll a,ll b){return a+b;}
ll id(){return 0;}
void SOLVE(){
  int n;
  cin>>n;
  HeavyLightDecomposition hld(n);
  rep(i,n-1){
    int u,v;
    cin>>u>>v;
    u--,v--;
    hld.add_edge(u,v);
  }
  hld.build();
  int q;
  cin>>q;
  vector<S>hoge(n,{1,0});
  lazy_segtree<S,op,e,ll,mapping,composition,id>seg(hoge);
  ll ans=0;
  while(q--){
    int u,v;
    cin>>u>>v;
    u--,v--;
    hld.path_query(u,v,[&](int a,int b){seg.apply(a,b,1);});
    hld.path_query(u,v,[&](int a,int b){ans+=seg.prod(a,b).sum;});
    debug(ans);
  }
  cout<<ans<<endl;
}