// Source: https://usaco.guide/general/io

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

struct pont{
    int x;
    int y;
};

signed main() {
    int n;cin>>n;
    vector<pont> v(n);
    map<int,int> sor,oszlop;
    for(int i = 0;i<n;i++){
        cin>>v[i].x>>v[i].y;
        sor[v[i].x]++;
        oszlop[v[i].y]++;
    }
    int cnt=0;
    for(int i = 0;i<n;i++){
        cnt+=(sor[v[i].x]-1)*(oszlop[v[i].y]-1);
    }
    cout<<cnt;
}