// In the name of GOD
#include <bits/stdc++.h>
using namespace std;
#define good exit(0);
#define nl endl
#define ios ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define sz(s) (int)s.size()
#define all(s) s.begin(), s.end()
#define pb push_back
#define bb begin()
#define ee end()
#define ff first
#define ss second
#define ll long long
#define db double
#define pii pair<int, int>
const int N = 3e5 + 555;
int n;
int x[11111], y[11111];
int ans;
int main(){
ios
cin >> n;
for(int i = 1; i <= n; ++i){
cin >> x[i] >> y[i];
}
for(int b = 1; b <= n; ++b){
for(int e = 1; e <= n; ++e){
for(int u = 1; u <= n; ++u){
if(b != e && b != u && e != u){
int q = 0;
if(x[b] != x[e] && y[b] == y[e] && x[b] == x[u] && y[b] != y[u]){
q = 1;
}
if(x[b] != x[e] && y[b] == y[e] && x[e] == x[u] && y[e] != y[u]){
q = 1;
}
ans += q;
}
}
}
}
cout << ans / 2;
return 0;
}
