#include <bits/stdc++.h>
using namespace std;
#define sp << " " <<
#define int long long
#define vi vector<int>
#define F(xxx,yyy) for (int xxx=1;xxx<=yyy;xxx++)
#define pii pair<int,int>
const int N = 5e5+1,inf = 1e18;
void solve() {
int n;
cin >> n;
map<int,int> xc,yc;
vector<pii> ps;
F(i,n) {
int a,b;
cin >> a >> b;
xc[a]++;
yc[b]++;
ps.push_back({a,b});
}
int ans = 0;
for (auto it : ps) {
ans+=(xc[it.first]-1)*(yc[it.second]-1);
}
cout << ans << endl;
}
signed main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#ifdef Local
freopen("in","r",stdin);
freopen("out","w",stdout);
#endif
int t = 1;
//cin >> t;
F(i,t) solve();
}
