func_code_string: #include <bits/stdc++.h>   using namespace std;   const int maxn = 10000;   int degree[maxn + 5];   int Cn_i(int n, int i) {     int up = 1;     int down = 1;     for (int t = n; t >= n - i + 1; t--) {       up = up * t;     }     for (int t = i; t >= 1; t--) {       down = down * t;     }     return up / down;   }   int main() {     int n;     while (scanf( %d , &n) != EOF) {       for (int i = 0; i < n; i++) degree[i] = 0;       for (int i = 0; i < n - 1; i++) {         int a, b;         scanf( %d%d , &a, &b);         degree[a]++;         degree[b]++;       }       int ans = 0;       for (int i = 0; i <= n; i++) {         if (degree[i] >= 2) {           ans += Cn_i(degree[i], 2);         }       }       printf( %d n , ans);     }     return 0;   }   