#include<bits/stdc++.h>
using namespace std;

#define endl '\n'
typedef long long LL;

void solve(){
    int n;
    cin >> n;
    vector<vector<int>> edge(n + 1);
    vector<pair<int,int>> adj(n + 1);
    vector<int> d(n + 1);
    for(int i = 1;i <= n;i++){
        int u,v;
        cin >> u >> v;
        adj[i] = {u,v};
        edge[u].push_back(v);
        edge[v].push_back(u);
        d[u]++;
        d[v]++;
    }
    queue<int> q;
    vector<bool> st(n + 1);
    for(int i = 1;i <= n;i++){
        if(d[i] == 1){
            q.push(i);
            st[i] = true;
        }
    }
    while(q.size()){
        int u = q.front();
        q.pop();
        for(auto v : edge[u]){
            d[v]--;
            if(d[v] == 1){
                q.push(v);
                st[v] = true;
            }
        }
    }
    d.assign(n + 1,0);
    for(int i = 1;i <= n;i++){
        auto [u,v] = adj[i];
        d[u]++,d[v]++;
    }

    vector<int> cnt(n + 1);
    for(int i = 1;i <= n;i++)cnt[d[i]]++;
    LL res = 0;
    for(int i = 1;i <= n;i++){
        auto [u,v] = adj[i];
        if(!st[u] && !st[v]){
            cnt[d[u]]--;
            cnt[d[v]]--;
            d[u]--;
            d[v]--;
            cnt[d[u]]++;
            cnt[d[v]]++;
            if(!cnt[5])res += cnt[1] + cnt[2] + cnt[3];
            cnt[d[u]]--;
            cnt[d[v]]--;
            d[u]++;
            d[v]++;
            cnt[d[u]]++;
            cnt[d[v]]++;
        }
    }
    cout << res << endl;


}   

int main(){
    ios::sync_with_stdio(false);
    cin.tie(NULL),cout.tie(NULL);
    int t = 1;
    //cin >> t;
    while(t--){
        solve();
    }

    return 0;
}