#include <bits/stdc++.h>
#define ll long long
#define INF 1000000000000000
#define mod 9929
using namespace std;
vector<vector<int>> v;
vector<int> ord, bl, al, vis;
bool f = 0;
void dfs(int x, int p){
vis[x] = 1;
ord.push_back(x);
for (auto el : v[x]){
if (vis[el] == 0){
dfs(el, x);
}
else if (vis[el] == 1 && el != p && f == 0){
int cur = (int)ord.size() - 1;
f = 1;
while (ord[cur] != el){
al.push_back(ord[cur]);
cur--;
}
al.push_back(el);
}
}
ord.pop_back();
}
ll de = 0, cnt = 0;
vector<ll> dd, cn;
void dfs2(int x, int p){
dd[x] = dd[p] + 1;
if (dd[x] > de) cnt = 0, de = dd[x];
if (dd[x] == de) cnt += 1;
ll d1 = dd[x], ch = 0;
for (auto el : v[x]){
if (el != p && bl[el] == 0){
ch++;
dfs2(el, x);
if (d1 + dd[el] - 2 * dd[x] > de) cnt = 0, de = d1 + dd[el] - 2 * dd[x];
if (d1 + dd[el] - 2 * dd[x] == de) cnt += cn[x] * cn[el];
if (dd[el] > d1) cn[x] = 0, d1 = dd[el];
if (dd[el] == d1) cn[x] += cn[el];
}
}
if (ch == 0) cn[x] = 1;
dd[x] = d1;
}
int main(){
int n, a, b;
cin>>n;
v.assign(n + 1, vector<int>()), vis.assign(n + 1, 0), bl.assign(n + 1, 0), dd.assign(n + 1, 0), cn.assign(n + 1, 0);
for (int i = 0; i < n; i++){
cin>>a>>b;
v[a].push_back(b);
v[b].push_back(a);
}
dd[0] = -1;
dfs(1, 0);
if (al.size() <= 2) assert(false);
for (auto el : al){
bl[el] = 1;
}
for (auto el : al){
dfs2(el, 0);
}
int k = al.size();
for (int i = 0; i < k; i++) al.push_back(al[i]);
map<ll, ll, greater<ll>> ma;
ll si = k / 2;
for (int i = k - si; i < k; i++){
ma[dd[al[i]] - i] += cn[al[i]];
}
for (ll i = k; i < 2 * k; i++){
while (1){
if (ma.begin()->second != 0) break;
ma.erase(ma.begin());
}
ll ss = dd[al[i]] + ma.begin()->first + i;
if (ss > de) cnt = 0, de = ss;
if (ss == de) cnt += ma.begin()->second * cn[al[i]];
ma[dd[al[i]] - i] += cn[al[i]];
ll oth = i - si;
ma[dd[al[oth]] - oth] -= cn[al[oth]];
}
cout<<cnt;
}
