// Born_To_Laugh - Hughie Do
#include <bits/stdc++.h>
#define alle(AC) AC.begin(), AC.end()
#define fi first
#define se second
using namespace std;
typedef long long ll;
[[maybe_unused]] const int MOD = 998244353, INF = 1e9 + 7;
const int maxn = 3e5 + 10;
map<int, int> cntcol, cntrow;
int n;
pair<int, int> a[maxn];
void solve(){
cin >> n;
for(int i=1; i<=n; ++i){
cin >> a[i].fi >> a[i].se;
cntcol[a[i].fi]++;
cntrow[a[i].se]++;
}
ll ans = 0;
for(int i=1; i<=n; ++i){
ans += (ll)(cntcol[a[i].fi] - 1) * (cntrow[a[i].se] - 1);
}
cout << ans << '\n';
}
signed main(){
// freopen("inp.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
solve();
}
