// KKGyak.cpp : This file contains the 'main' function. Program execution begins and ends there.
//
using namespace std;

#include <iostream>
#include <map>
#include <set>
#include <unordered_set>
#include <vector>
#include <algorithm>
#include <unordered_map>

#define int long long

signed main()
{
    int n;
    cin >> n;
	vector<vector<int>> rows(200001);
	vector<vector<int>> coloumns(200001);
	for (size_t i = 0; i < n; i++)
	{
		int a, b;
		cin >> a >> b;
		rows[a].push_back(b);
		coloumns[b].push_back(a);
	}
	int res = 0;
	for (size_t i = 0; i < rows.size(); i++)
	{
		for (size_t j = 0; j < rows[i].size(); j++)
		{
			int coloumn = rows[i][j];
			for (size_t k = 0; k < coloumns[coloumn].size(); k++)
			{
				int newRow = coloumns[coloumn][k];
				if (newRow != i) {
					res += rows[newRow].size() - 1;
				}
			}
		}
	}
	cout << res;
}

// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu

// Tips for Getting Started: 
//   1. Use the Solution Explorer window to add/manage files
//   2. Use the Team Explorer window to connect to source control
//   3. Use the Output window to see build output and other messages
//   4. Use the Error List window to view errors
//   5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
//   6. In the future, to open this project again, go to File > Open > Project and select the .sln file