#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#define intt long long
#define pb push_back
#define endl "\n"
#define ALL(x) x.begin(), x.end()
void solve() {
int n, x, y;
cin >> n;
set<vector<int>> se;
for (int i = 0; i < n; i++){
cin >> x >> y;
se.insert({x, y});
}
map<intt, intt> mx, my;
for (auto mpmppmpmp : se){
mx[mpmppmpmp[0]]++;
my[mpmppmpmp[1]]++;
}
intt ans = 0;
for (auto mpmppmpmp : se){
ans += (mx[mpmppmpmp[0]] - 1) * (my[mpmppmpmp[1]] - 1);
}
cout << ans << endl;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
intt tst = 1;
// cin >> tst
while (tst--) {
solve();
}
}
