#include <bits/stdc++.h>
using namespace std;
#define futaba ios_base::sync_with_stdio(false); cin.tie(NULL);
#define rio return 0;
#define ll long long
// Fun things are fun. //
ll x[300005], y[300005];
int main() {
// freopen("generate.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
futaba
int n;
cin >> n;
map<ll, ll> cntx, cnty;
for(int i = 1; i <= n; i++) {
cin >> x[i] >> y[i];
cntx[x[i]]++;
cnty[y[i]]++;
}
ll ans = 0;
for(int i = 1; i <= n; i++) ans += ((cntx[x[i]] - 1) * (cnty[y[i]] - 1));
cout << ans << '\n';
rio
}
