func_code_string: #include <bits/stdc++.h>   using namespace std;   const int sz = 1e5 + 10, mod = 1e9 + 7, inf = 2e9;   struct re {     int to, va;     bool co;   };   re nel;   int n, anch = 1, anzn = 1, cuq, si[sz], sq, cu, lg, rg, add;   vector<re> sv[sz];   vector<pair<int, pair<int, int> > > pa[sz];   pair<int, int> dot[2][sz * 8];   pair<int, int> recalc(pair<int, int> l, pair<int, int> r) {     pair<int, int> re;     re.first = (1ll * l.first * r.first) % mod;     re.second = l.second + r.second;     return re;   }   void build(int nu, int l, int r) {     dot[cu][nu].first = 1, dot[cu][nu].second = 0;     if (l < r) {       int mid = (l + r) / 2;       build(nu * 2, l, mid);       build(nu * 2 + 1, mid + 1, r);     }   }   void cha(int nu, int l, int r) {     if (l == r) {       dot[cu][nu].first = (1ll * dot[cu][nu].first * add) % mod,       dot[cu][nu].second++;     } else {       int mid = (l + r) / 2;       if (lg <= mid)         cha(nu * 2, l, mid);       else         cha(nu * 2 + 1, mid + 1, r);       dot[cu][nu] = recalc(dot[cu][nu * 2], dot[cu][nu * 2 + 1]);     }   }   pair<int, int> que(int nu, int l, int r) {     if (l >= lg and r <= rg)       return dot[cu][nu];     else if (l > rg or r < lg)       return make_pair(1, 0);     else {       int mid = (l + r) / 2;       return recalc(que(nu * 2, l, mid), que(nu * 2 + 1, mid + 1, r));     }   }   int pow(int x, int y) {     if (y == 0)       return 1;     else if (y % 2 == 1)       return (1ll * pow(x, y - 1) * x) % mod;     else {       int t = pow(x, y / 2);       return (1ll * t * t) % mod;     }   }   void siz(int v, int pr) {     si[v] = 1;     for (int a = 0; a < sv[v].size(); a++) {       int ne = sv[v][a].to;       if (ne != pr) {         siz(ne, v);         si[v] += si[ne];       }     }   }   int find_ce(int v, int pr) {     for (int a = 0; a < sv[v].size(); a++) {       int ne = sv[v][a].to;       if (ne != pr and si[ne] > cuq / 2) return find_ce(ne, v);     }     if (pr != -1) si[pr] = cuq - si[v];     return v;   }   void dfs2(int v, int pr, int rq, int bq, int le) {     pa[sq].push_back(make_pair(le, make_pair(rq, bq)));     for (int a = 0; a < sv[v].size(); a++) {       int ne = sv[v][a].to, r = 0, b = 0, nle = sv[v][a].va;       if (sv[v][a].co == 0)         r++;       else         b++;       if (ne != pr) dfs2(ne, v, rq + r, bq + b, (1ll * le * nle) % mod);     }   }   void dfs(int v, int q) {     cuq = q;     siz(v, -1);     int ce = find_ce(v, -1);     sq = 1;     pa[0].push_back(make_pair(1, make_pair(0, 0)));     for (int a = 0; a < sv[ce].size(); a++) {       int ne = sv[ce][a].to, rq = 0, bq = 0, le = sv[ce][a].va;       if (sv[ce][a].co == 0)         rq = 1;       else         bq = 1;       dfs2(ne, ce, rq, bq, le), sq++;     }     q++;     cu = 0, build(1, 0, q * 2);     cu = 1, build(1, 0, q * 2);     for (int a = 0; a < sq; a++) {       for (int b = 0; b < pa[a].size(); b++) {         int le = pa[a][b].first, rq = pa[a][b].second.first,             bq = pa[a][b].second.second;         cu = 0, lg = 0, rg = -(bq - rq * 2) + q;         int qq;         pair<int, int> ans = que(1, 0, q * 2);         qq = ans.second, anch = (1ll * anch * ans.first) % mod;         cu = 1, lg = 0, rg = -(bq * 2 - rq) - 1 + q;         ans = que(1, 0, q * 2);         qq -= ans.second, anzn = (1ll * anzn * ans.first) % mod;         anch = (1ll * anch * pow(le, qq)) % mod;       }       for (int b = 0; b < pa[a].size(); b++) {         int le = pa[a][b].first, rq = pa[a][b].second.first,             bq = pa[a][b].second.second;         cu = 0, lg = (bq - rq * 2) + q, add = le;         cha(1, 0, q * 2);         cu = 1, lg = (bq * 2 - rq) + q, add = le;         cha(1, 0, q * 2);       }       pa[a].clear();     }     while (sv[ce].size() > 0) {       int ne = sv[ce].back().to;       for (int b = 0; b < sv[ne].size(); b++)         if (sv[ne][b].to == ce) sv[ne].erase(sv[ne].begin() + b);       sv[ce].pop_back();       dfs(ne, si[ne]);     }   }   int main() {     cin >> n;     for (int a = 0; a < n - 1; a++) {       int u, v, va, co;       scanf( %d%d%d%d , &u, &v, &va, &co);       u--, v--;       nel.to = v, nel.va = va, nel.co = co;       sv[u].push_back(nel);       nel.to = u, sv[v].push_back(nel);     }     dfs(0, n);     int ans = (1ll * anch * pow(anzn, mod - 2)) % mod;     cout << ans;   }   