#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i,n) for(long long (i)=0;(i)<(n);++(i))
#define ref(i,a,b) for (long long (i)=(a); (i)<=(b); ++(i))
#define endl '\n'
#define st first
#define nd second
#define pb push_back
#define mp make_pair
const long long mx=3e5+5;
// FREOPEN UNUTMA
long long n;
pair <long long,long long> a[mx];
int main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);
/*freopen("triangles.in", "r", stdin);
freopen("triangles.out", "w", stdout); */
//
unordered_map <long long,long long> mp;
unordered_map <long long,long long> mp2;
cin >> n;
rep(i,n){
cin >> a[i].first;
cin >> a[i].second;
mp.insert(pair <long long,long long>(a[i].first,a[i].nd));
mp2.insert(pair<long long,long long>(a[i].nd,a[i].st));
}
long long ans=0;
for(long long i=0;i<n;++i){
ans+=(mp.count(a[i].first)-1)*(mp2.count(a[i].nd)-1);
// cout << mp.count(a[i].first) <<" "<< mp2.count(a[i].nd)<< endl;
}
cout << ans << endl;
}
