#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

vector<vector<int>> x(200001);
vector<vector<int>> y(200001);

int main()
{
    int n;
    cin>>n;
    int a, b;
    vector<int> xek(n+1);
    vector<int> yok(n+1);
    for(int i=1; i<=n; i++)
    {
        cin>>a>>b;
        x[a].push_back(i);
        y[b].push_back(i);
        xek[i] = a;
        yok[i] = b;
    }
    int db=0;
    for(int i=1; i<=n; i++)
    {
        if(x[xek[i]].size() && y[yok[i]].size())
        {
            db+=(x[xek[i]].size()-1)*(y[yok[i]].size()-1);
        }
    }
    cout<<db;
    return 0;
}