func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, i, j, k, l, m, t;     vector<int> a[10001];     cin >> n;     for (i = 1; i < n; i++) {       cin >> m >> t;       a[m].push_back(t);       a[t].push_back(m);     }     l = 0;     m = 0;     int b[30001], c[30001];     for (t = 1; t <= n; t++) {       j = 0;       for (i = 0; i < a[t].size(); i++) {         j++;         b[j] = a[t][i];       }       l = 0;       for (i = 1; i <= a[t].size(); i++) {         for (j = 0; j < a[b[i]].size(); j++) {           l++;           c[l] = a[b[i]][j];         }       }       for (i = 1; i <= l; i++)         if (c[i] > t) m++;     }     cout << m << endl;   }   