#include <iostream>
#include <fstream>
#include <algorithm>
#include <bitset>

using namespace std;
ifstream fin ("trapez.in");
ofstream fout("trapez.out");
pair<int, int> l[1001],c[1001];
long long s,n,i,x,y;

void rezolvare(pair<int, int> v[])
{
    int sol[1001];int m=0;v[0].first=-1;
    for(int i=1;i<=n;i++)
    {
        if(v[i].first!=v[i-1].first)
        {
            m++; sol[m]=0;
        }
        sol[m]++;
    }
    for(int i=1;i<m;i++)
        for(int j=i+1;j<=m;j++)
            s+=(1LL*sol[i]*sol[j]*(sol[i]-1)*(sol[j]-1))/4;
}

int main()
{
    fin>>n;
    for(i=1;i<=n;i++)
    {
        fin>>x>>y;
        l[i].first=x;l[i].second=y;
        c[i].second=x;c[i].first=y;
    }
    sort(l+1, l+n+1);sort(c+1, c+n+1);
    rezolvare(l);
    rezolvare(c);
    fout<<s;
    fin.close();
    fout.close();
    return 0;
}