func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 10005;   vector<int> gr[N];   int ans = 0;   void dfs(int v, int p = -1) {     for (int to : gr[v])       if (to != p) {         dfs(to, v);         ans += (gr[to].size() - 1);       }     ans += ((gr[v].size() - (v != 1)) * (gr[v].size() - 1 - (v != 1))) / 2;   }   int main() {     int n;     scanf( %d , &n);     for (int i = 1; i < n; ++i) {       int a, b;       scanf( %d%d , &a, &b);       gr[a].push_back(b);       gr[b].push_back(a);     }     dfs(1);     cout << ans;     return 0;   }   