#include <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using pii = pair<int, int>;

int main() {
  int N;
  cin >> N;
  vector<vector<int>> g(N);
  rep(i, N-1) {
    int u, v;
    cin >> u >> v;
    u--; v--;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  auto dfs = [&](auto dfs, int s, int n, vector<int> &seen) {
    seen.push_back(s);
    if (n == 3)
      return;
    for (int d : g[s]) {
      if (find(seen.begin(), seen.end(), d) != seen.end())
	continue;
      dfs(dfs, d, n+1, seen);
    }
    return;
  };
  set<pii> p;
  rep(i, N) {
    vector<int> seen;
    dfs(dfs, i, 0, seen);
    for (int j : seen) {
      if (j == i) continue;
      if (i < j)
	p.insert({i, j});
      else
	p.insert({j, i});
    }
  }
  cout << (int)p.size() << endl;
  return 0;
}