#include <iostream>
#include <list>
#include <fstream>
#include <algorithm>
#include <cmath>
#include <cstdlib>
#include <iomanip>
#include <map>
#include <set>
#define eps 0.1
using namespace std;
long long prod(long long x){
	long long t=0;
	long long res=1;
	while(true){
		res*=x%10;
		x/=10;
		if (x==0)
			break;
	}
	return res;
}
int max1(int x, int y){
	return (x>y?x:y);
}
int min1(int x, int y){
	return (x<y?x:y);
}
long long func1(long long x){
	return (x*(x-1))/2;
}
int main()
{
    //ifstream fin("file.in");
    //ofstream fout("file.out");
    long long n, m;
    long long res=0;
    long long min, max;


   // cin.sync_with_stdio(false);
    //cout.sync_with_stdio(false);
    //int[] sett;
    //map<int, int> mapp;
    int massx[300000]={};
    int massy[300000]={};
    bool b1[300000]={};
    cin >> n;
    int ll;
    long long tres=0;
    long long resx=0;
    long long resy=0;
    map<long long, long long> mappx;
    map<long long, long long> mappy;
    map<pair<long long, long long>, long long> tmapp;
    long long xx, yy;
    for (int i=0; i<n; i++){
    	cin >> xx >> yy;
    	mappx[xx]++;
    	mappy[yy]++;
    	tmapp[{xx,yy}]++;
    }
    for (int i=0; i<n; i++)
    	//cout << mass[i];
    max;
	for(auto&mm:mappx){
		resx+=func1(mm.second);
	}
	for(auto&mm:mappy){
		resy+=func1(mm.second);
	}
	for(auto&mm:tmapp){
		tres+=func1(mm.second);
	}

    bool b;
    int prev;

    cout << resy+resx-tres;
    //fin.close();
    //fout.close();
    return 0;
}