#include <bits/stdc++.h>
using namespace std;
vector<int> adj[200010];
long long int ans = 0LL;
int odd = 0, sz[200010] = {};
void dfs(int cur, int par = -1, int ht = 0) {
  sz[cur]++;
  for (int u : adj[cur]) {
    if (u == par) continue;
    dfs(u, cur, ht ^ 1);
    sz[cur] += sz[u];
  }
  if (ht) odd++;
}
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n - 1; i++) {
    int x, y;
    scanf("%d %d", &x, &y);
    adj[x].push_back(y);
    adj[y].push_back(x);
  }
  dfs(1);
  for (int i = 1; i <= n; i++) ans += (1LL) * sz[i] * (n - sz[i]);
  ans += (1LL) * odd * (n - odd);
  printf("%lld\n", ans / 2);
  return 0;
}
