#include <bits/stdc++.h>
using namespace std;
using ll = long long;
void solve()
{
// ifstream fin("triangles.in");
// ofstream fout("triangles.out");
int n; cin >> n;
map<int, int> x, y;
vector<pair<int, int>> points;
for (int i = 0; i < n; ++i) {
int x1, y1; cin >> x1 >> y1;
++x[x1], ++y[y1];
points.emplace_back(x1, y1);
}
ll ans = 0;
for (auto p : points) {
ans += (x[p.first]-1) * (y[p.second]-1);
}
cout << ans;
}
signed main()
{
ios_base::sync_with_stdio(false); cin.tie(nullptr);
// ll t; cin >> t; while(t--)
solve();
}
