#include <bits/stdc++.h>
using namespace std;
#define int long long
#define fi first
#define se second
int n,a[200005], b[200005];
int cur = 1, tr[200005], dc[200005];
int c = 100000;
pair<int,int> store[200005];
int f(int u){
	return (a[u] < 0 ? u : a[u] = f(a[u]));
}
void m(int u,int v){
	u = f(u); v = f(v);
	if(u == v) return;
	if(a[u] > a[v]) swap(u,v);
	a[u] += a[v]; a[v] = u;
}
signed main(){
	cin >> n;
	for(int i = 1 ; i <= 200004 ; i ++) a[i] = -1;
	for(int i = 1 ; i <= n ; i ++){
		int x, y;
		cin >> x >> y;
		b[x] = 1; b[c + y] = 1;
		m(x, c + y);
	}
	int ans = 0;
	for(int i = 1 ; i <= 200004 ; i ++){
		if(b[i]){
			if(!dc[f(i)]){
				dc[f(i)] = 1;
				tr[f(i)] = cur;
				cur ++;
			}
			if(i <= c) store[tr[f(i)]].fi ++;
			else store[tr[f(i)]].se ++;
		}
	}
	for(int i = 1 ; i < cur ; i ++)
		ans += store[i].fi * store[i].se;
	cout << ans - n;
}
