/**
* author : pham van sam
* created : 27 August 2023 (Sunday)
**/
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 3e5 + 5;
int N, x[MAXN], y[MAXN];
map <int, int> cnt_x, cnt_y;
void you_make_it(void) {
cin >> N;
for (int i = 1; i <= N; ++i) {
cin >> x[i] >> y[i];
cnt_x[x[i]]++, cnt_y[y[i]]++;
}
long long ans = 0;
for (int i = 1; i <= N; ++i) {
ans += 1LL * (cnt_x[x[i]] - 1) * (cnt_y[y[i]] - 1);
}
cout << ans;
}
signed main() {
#ifdef LOCAL
freopen("TASK.inp", "r", stdin);
freopen("TASK.out", "w", stdout);
#endif
auto start_time = chrono::steady_clock::now();
cin.tie(0), cout.tie(0) -> sync_with_stdio(0);
you_make_it();
auto end_time = chrono::steady_clock::now();
cerr << "\nExecution time : " << chrono::duration_cast <chrono::milliseconds> (end_time - start_time).count() << "[ms]" << endl;
return (0 ^ 0);
}
// Dream it. Wish it. Do it.
