#include <iostream>
#include <set>
#include <map>
#include <algorithm>
using namespace std;
#define sz(s) (int)(s.size())
#define eb emplace_back
#define all(x) x.begin(), x.end()
const int N = 2e6;
const int NN = 4e3;
#define ll long long
map <int, int> cntx, cnty;
int x[N], y[N];
void solve() {
int n;
cin >> n;
for (int i = 1; i <= n; ++ i) {
cin >> x[i] >> y[i];
++cntx[x[i]];
++cnty[y[i]];
}
ll res = 0;
for (int i = 1; i <= n; ++ i)
res += ((cntx[x[i]] - 1) * (cnty[y[i]] - 1));
cout << res;
}
int main () {
solve();
return 0;
}
