#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
struct ret {
vector<ll> c = {};
ll suma = 0, summ = 0;
void expand(int val = 0) {
summ += suma;
suma += val;
c.push_back(val);
}
ret(int val) {
expand(val);
}
ll& operator[](int idx) {
return c[c.size() - 1 - idx];
}
[[nodiscard]] int siz() {
return c.size();
}
};
ll combine(ret& tot, ret sml) {
ll ans = 0;
for (int i = 0; i < sml.siz(); i++) {
ans += tot.suma * sml[i] * i;
ans += tot.summ * sml[i];
tot[i] += sml[i];
}
tot.suma += sml.suma;
tot.summ += sml.summ;
return ans;
}
ll ans = 0;
ret dfs(int v, int p, vector<vector<int>> &G) {
ret curr(1);
for (int u : G[v]) {
if (u == p)
continue;
ret sml = dfs(u, v, G);
sml.expand();
if (sml.siz() > curr.siz())
swap(sml, curr);
ans += combine(curr, sml);
}
return curr;
}
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
int n, m;
cin >> n >> m;
vector<vector<int>> G(n + 1);
for (int i = 0; i < m; i++) {
int u, v;
cin >> u >> v;
G[u].push_back(v);
G[v].push_back(u);
}
dfs(1, 0, G);
cout << ans << '\n';
}
/*
5 4
1 2
1 3
2 4
2 5
*/
