#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
#define ld long double
// 217
// 44
using namespace std;
const int MAXN = (int) 3e5;
pair <int, int> pts[MAXN + 1];
map <int, int> frx, fry;
int main() {
//ifstream cin("A.in");
//ofstream cout("A.out");
int i, n;
ios::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
cin >> n;
for(i = 1; i <= n; i++) {
int x, y;
cin >> x >> y;
pts[i] = {x, y};
frx[x]++;
fry[y]++;
//fr[{x, y}]++;
}
ll ans = 0;
for(i = 1; i <= n; i++) {
ans += 1LL * (frx[pts[i].first] - 1) * (fry[pts[i].second] - 1);
}
cout << ans;
//cin.close();
//cout.close();
return 0;
}
