#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int N;
vector<pair<int, int>> points;
int countRightTriangles() {
int count = 0;
for (int i = 0; i < N; i++) {
for (int j = i + 1; j < N; j++) {
for (int k = j + 1; k < N; k++) {
int x1 = points[i].first, y1 = points[i].second;
int x2 = points[j].first, y2 = points[j].second;
int x3 = points[k].first, y3 = points[k].second;
if ((x1 == x2 && y2 == y3) || (x1 == x3 && y1 == y2) || (x2 == x3 && y1 == y3)) {
count++;
}
}
}
}
return count;
}
int main() {
cin >> N;
points.resize(N);
for (int i = 0; i < N; i++) {
cin >> points[i].first >> points[i].second;
}
cout << countRightTriangles() << endl;
return 0;
}
