#include <bits/stdc++.h>
using namespace std;
const int maxn = 3e5 + 10;
int n, u, v, dp[maxn], d[2];
long long f[maxn], ans, sum;
vector<int> a[maxn];
void dfs(int nod, int pa, int x) {
  d[x]++;
  for (int i : a[nod]) {
    if (i != pa) {
      dfs(i, nod, x ^ 1);
      dp[nod] += dp[i];
      f[nod] += (f[i] + dp[i]);
    }
  }
  for (int i : a[nod]) {
    if (i != pa) {
      ans += (f[nod] - f[i] - dp[i]) * dp[i];
    }
  }
  ans += f[nod];
  dp[nod]++;
  return;
}
int main() {
  scanf("%d", &n);
  for (int i = 1; i < n; i++) {
    scanf("%d%d", &u, &v);
    a[u].push_back(v);
    a[v].push_back(u);
  }
  dfs(1, 0, 0);
  printf("%lld\n", (ans + (1ll * d[0] * d[1])) / 2);
}
