func_code_string: #include<bits/stdc++.h>      #define ll long long   #define rep(A,B,C) for(A=B;A<C;++A)   #define pii pair<int,int>   #define pll pair<ll,ll>      #define fi first   #define se second   #define all(A) A.begin(),A.end()      using namespace std;      /////////////////////////////////////////////////////   #define vv vector   #define Nmx 303030   #define lNmx 20      ll N,M;   vv<pll> uvv[Nmx + 3];   pll xyv[Nmx + 3];   ll dblp[Nmx + 3][lNmx + 3];   ll dps[Nmx + 3];   ll mked[Nmx + 3], mkcm[Nmx + 3];   vv<pll> cmv[Nmx + 3];   ll an[Nmx + 3];   ll i, j, k;         ll dfs1(ll a,ll p,ll d){              dblp[a][0] = p;       dps[a] = d;       ll i = 0, pi = 0;       ll c = 0;       c += mked[a] - mkcm[a];       rep(i,0,uvv[a].size()){           ll b = uvv[a][i].fi;           if(b==p){               pi = i;               continue;           }           ll rb= dfs1(b, a, d + 1);           //printf( %lld,%lld,%lld n , a, b, rb);           uvv[a][i].se = rb;           c += rb;           //assert(false);       }       an[a] = c;       uvv[a][pi].se = c - mkcm[a];       //printf( %lld,%lld,%lld,%lld n , a, p, d,uvv[1][0].se);       return uvv[a][pi].se;   }      void dblinit(){       ll i, j;       rep(j,0,lNmx)           rep(i,0,N+1)               dblp[i][j + 1] = dblp[dblp[i][j]][j];   }      pll lcap(ll a,ll b){       if(a==b)           return {-1, -1};       if(dps[a]<dps[b])           swap(a, b);       ll i = lNmx;       while(dps[a]-dps[b]>1){           if((1<<i)<=dps[a]-dps[b]-1)               a = dblp[a][i];           --i;       }       if(dps[a]>dps[b]){           if(dblp[a][0]==b)               return {a, -1};           a = dblp[a][0];       }       i = lNmx;       while(i>=0){           if(dblp[a][i]!=dblp[b][i]){               a = dblp[a][i];               b = dblp[b][i];           }           --i;       }       if(a>b)           swap(a, b);       return {a, b};   }      ll calc(ll a){       ll i;       map<ll, ll> mp;       rep(i,0,uvv[a].size()){           mp[uvv[a][i].fi] = i;       }       ll ans = 0;       map<pll, ll> mp2;       rep(i,0,cmv[a].size()){                      ll aa = --an[a];           ll p1 = cmv[a][i].fi, p2 = cmv[a][i].se;           //printf( %lld:%lld,%lld,%lld,%lld  ,a, i,p1,p2, an[a]);           if(p1!=-1){               ll I = mp[p1];               aa -= --uvv[a][I].se;               //printf( a%lld, , uvv[a][I].se);           }           if(p2!=-1){               ll I = mp[p2];               aa -= --uvv[a][I].se;               //printf( b%lld, , uvv[a][I].se);           }           if(p1!=-1&&p2!=-1){               //printf( c%lld, , mp2[cmv[a][i]]);               aa += mp2[cmv[a][i]]++;           }           //printf(  n );           ans += aa;       }       return ans;   }         void solve(){       dfs1(1, 0, 1);       dblinit();              //assert(false);       rep(i,0,M){           pll xy = xyv[i];           if(xy.fi>xy.se)               swap(xy.fi, xy.se);           ++mked[xy.fi];           ++mked[xy.se];           //printf( ccc%lld,%lld, n , xy.fi, xy.se);           if(xy.fi==xy.se){               cmv[xy.fi].push_back({-1, -1});               ++mkcm[xy.fi];               continue;           }           pll cmp = lcap(xy.fi, xy.se);           //printf( ddd%lld,%lld,%lld n , cmp.fi, cmp.se,dblp[cmp.fi][0]);                      ll cm = dblp[cmp.fi][0];           cmv[cm].push_back(cmp);           ++mkcm[cm];       }              dfs1(1, 0, 1);       /*rep(i,0,N+1){           printf(  n%lld-%lld: n , i, an[i]);           rep(j,0,uvv[i].size()){               printf( %lld,%lld n , uvv[i][j].fi, uvv[i][j].se);           }       }*/       ll ans=0;       rep(i,0,N+1){           ll a = calc(i);           //printf( %lld,%lld n , i, a);           ans += a;       }          printf( %lld n , ans);   }            int main(){       scanf( %lld , &N);              rep(i,1,N){           ll u, v;           scanf( %lld%lld , &u, &v);           uvv[u].push_back({v, 0});           uvv[v].push_back({u, 0});       }       uvv[1].push_back({0, 0});       scanf( %lld , &M);       rep(i,0,M){           ll u, v;           scanf( %lld%lld , &u, &v);           xyv[i] = {u, v};       }       solve();          return 0;   }