#include <bits/stdc++.h>
using namespace std;
vector<long long> g[(long long)3e5], a((long long)3e5);
long long i, n, x, y, r;
void b(long long p, long long q, long long m) {
  a[p]++, r += m;
  for (auto j : g[p])
    if (j != q) b(j, p, m ^ 1), a[p] += a[j];
}
int main() {
  for (cin >> n, i = 1; i < n; i++)
    cin >> x >> y, g[x].push_back(y), g[y].push_back(x);
  b(1, 0, 0), r *= (n - r);
  for (i = 1; i <= n; i++) r += a[i] * (n - a[i]);
  cout << r / 2;
}
