https://atcoder.jp/contests/abc173/tasks/abc173_f
#include <bits/stdc++.h>
using namespace std;
#define int long long
void read (int &x) {
char ch = getchar(); x = 0;
while (!isdigit(ch)) ch = getchar();
while (isdigit(ch)) x = x * 10 + ch - 48, ch = getchar();
} const int N = 2e5 + 10;
int n, ans, res;
signed main() {
read (n);
for (int i = 1; i <= n; ++i) res += i * (n - i + 1);
for (int i = 1, u, v; i < n; ++i) {
read (u), read (v);
if (u > v) swap (u, v);
res -= u * (n - v + 1);
} return printf ("%lld
", res), 0;
}