#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<cstring>
#include<cstdio>
using namespace std;
const int MaxN = int(1e6) + 123;
vector <int> v;
int a[MaxN], b[MaxN], x[MaxN], y[MaxN], n;
long long ans;
int main (){
//freopen("triangles.in", "r", stdin);
//freopen("triangles.out", "w", stdout);
cin >> n;
for (int i = 1; i <= n; i++)
{
cin >> x[i] >> y[i];
v.push_back (x[i]);
v.push_back (y[i]);
}
sort (v.begin(),v.end());
v.erase (unique (v.begin(), v.end()), v.end());
for (int i = 1; i <= n; i++) {
x[i] = lower_bound (v.begin(), v.end(), x[i]) - v.begin() + 1;
y[i] = lower_bound (v.begin(), v.end(), y[i]) - v.begin() + 1;
a[x[i]]++;
b[y[i]]++;
}
for(int i = 1; i <= n; i++)
ans += (a[x[i]] - 1) * (b[y[i]] - 1);
cout << ans;
return 0;
}
