#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define vi vector<int>
#define pb push_back
int main()
{
ll n;
cin >> n;
map<ll, vector<ll>> x;
map<ll, vector<ll>> y;
map<ll, ll> counts;
ll ans = 0;
for (int i = 0; i < n; i++)
{
ll a, b;
cin >> a >> b;
x[a].pb(b);
y[b].pb(a);
}
for (auto i : x)
{
ll elementsss = 0;
ll currsum = 0;
for (auto j : i.second)
{
int sz = y[j].size();
sz--;
currsum += sz;
elementsss++;
}
ans += currsum * (elementsss - 1);
}
cout << ans;
// x: 0 = 0, 1; 1 = 0 y: 0 = 0,1 1 = 0
// x: 0 = 2; 1 = 2;
// y: 0 = 2; 1 = 2;
// if found a coordinate sharing x/y find a coordinate in which it either shares y/x
// example: 0 1 ,0 2
/*
x..
...
x.x
*/
//
}
