#include "bits/stdc++.h"
using namespace std;
/*
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using ordered_set = tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>;
*/
#define all(x) begin(x), end(x)
#define sz(x) (int)x.size()
using ll = long long;
const int mod = 1e9+7;
void solve(int tc) {
int n;
cin >> n;
vector<pair<ll, ll>> v(n);
map<ll, ll> cnta, cntb;
for (auto &[a, b] : v) {
cin >> a >> b;
++cnta[a], ++cntb[b];
}
ll ans = 0;
for (auto &[a, b] : v) {
ans += (cnta[a]-1) * (cntb[b]-1);
}
cout << ans << '\n';
}
signed main() {
ios_base::sync_with_stdio(false); cin.tie(NULL);
int tc = 1;
//cin >> tc;
for (int i = 1; i <= tc; ++i) solve(i);
return 0;
}
