#include <bits/stdc++.h>
#define fr first
#define se second
using namespace std;
const long long N = 3e5 + 7;
const long long inf = 1e9 + 7;
const long long mod = 1e9 + 7;
long long n;
long long res;
pair<long long, long long> d[N];
int main()
{
/// freopen("input.txt", "r", stdin);
/// freopen("output.txt", "w", stdout);
ios_base::sync_with_stdio( false );
cin >> n;
for(int i = 1; i <= n; i ++){
cin >> d[i].fr >> d[i].se;
}
for(int i = 1; i <= n; i ++){
for(int j = 1; j <= n; j ++){
for(int k = 1; k <= n; k ++){
if(i == j || i == k || j == k){
continue;
}
pair<long long, long long> a = d[i];
pair<long long, long long> b = d[j];
pair<long long, long long> c = d[k];
res += (a.fr == b.fr && b.se == c.se);
}
}
}cout << res << "\n";
}
