#include <iostream>
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const ll maxn = 2*1e5+5, INF = 4e18+9;
struct point{
ll x, y;
};
void solve(){
int n;
cin >> n;
vector<point> a(n+1);
for(int i = 1; i <= n; i++){
cin >> a[i].x >> a[i].y;
}
map<int, int> mpx, mpy;
for(int i = 1; i <= n; i++){
mpx[a[i].x]++;
mpy[a[i].y]++;
}
ll ans = 0;
for(int i = 1; i <= n; i++){
ans += (long long)(mpx[a[i].x]-1) * (mpy[a[i].y]-1);
}
cout << ans;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
solve();
}
