#include "bits/stdc++.h"
using namespace std;
int n;
vector <vector <int>> v;
int main(){
ios::sync_with_stdio(false); cin.tie(nullptr);
cin >> n;
v.resize(n+1);
for(int i = 1; i <= n; i++){
int u1, u2;
cin >> u1 >> u2;
v[u1].push_back(u2);
v[u2].push_back(u1);
}
queue <int> q;
int ans = 0, mx = 0;
for(int i = 1; i <= n; i++){
vector <int> dis(n+1,-1), dis1(n+1,0);
dis[i] = 0, dis1[i] = 1;
q.push(i);
while(!q.empty()){
int x = q.front();
q.pop();
for(auto j : v[x]){
if(dis[j] == -1){
dis[j] = dis[x]+1;
dis1[j] = dis1[x];
q.push(j);
}
else if(dis[j] == dis[x]+1){
dis1[j] += dis1[x];
}
}
}
// cout << i << '\n';
for(int j = 1; j <= n; j++){
// cout << j << ' ' << dis[j] << "\n";
if(dis[j] == mx) ans += dis1[j];
else if(dis[j] > mx) ans = dis1[j], mx = dis[j];
}
}
cout << ans/2 << '\n';
}
