#include <bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL);
#define ll long long
#define rep(i, n) for(int i = 0 ; i < n ; i++)
#define all(a) a.begin(), a.end()
unordered_map<int, int> X;
unordered_map<int, int> Y;
int main() {
fast
int n; cin>>n;
pair<int, int> coor[n+1];
rep(i, n){
int x, y; cin>>x>>y;
X[x]++;
Y[y]++;
coor[i+1].first = x;
coor[i+1].second = y;
}
ll ans = 0;
for(int i = 1 ; i <= n ; i++){
int x = coor[i].first;
int y = coor[i].second;
ans += (X[x] - 1)*(Y[y] - 1);
}
cout<<ans;
return 0;
}
