#include <iostream>
#include <vector>
#include <map>
using namespace std;
/**
* Masala: To'g'ri burchakli uchburchaklar
* Vaqt murakkabligi: O(N log N)
*/
int main() {
// Kiritish va chiqarishni tezlashtirish
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
cin >> n;
vector<pair<int, int>> stars(n);
map<int, int> countX, countY;
// Har bir koordinata bo'yicha yulduzlar sonini hisoblash
for (int i = 0; i < n; i++) {
cin >> stars[i].first >> stars[i].second;
countX[stars[i].first]++;
countY[stars[i].second]++;
}
long long total_triangles = 0;
// Har bir yulduzni to'g'ri burchak cho'qqisi sifatida tekshirish
for (int i = 0; i < n; i++) {
long long currentX = countX[stars[i].first];
long long currentY = countY[stars[i].second];
// (nx - 1) * (ny - 1) formula orqali uchburchaklar sonini qo'shish
total_triangles += (currentX - 1) * (currentY - 1);
}
cout << total_triangles << endl;
return 0;
}
