#include<bits/stdc++.h>
#define M 100000
#define N 200005
using namespace std;
vector<int>son[N];
int E,L,R,mark[N];
void dfs(int x,int flg){
	E++;
	if(mark[x])return;
	mark[x]=1;
	if(flg)L++;
	else R++;
	for(int i=0;i<son[x].size();i++){
		int y=son[x][i];
		dfs(y,!flg);
	}
}
int main(){
	int n,x,y;
	scanf("%d",&n);
	for(int i=1;i<=n;i++)scanf("%d%d",&x,&y),son[x].push_back(y+M),son[y+M].push_back(x);
	long long ans=0;
	for(int i=1;i<=M;i++){
		if(!mark[i]){
			E=L=R=0;
			if(son[i].size()==0)continue;
			dfs(i,1);
			if(L<2||R<2)continue;
			E/=2;
			ans+=1ll*L*R-E;
		}
	}
	printf("%lld\n",ans);
	return 0;
}