#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <queue>
#include <deque>
#include <cstring>
#include <string>
#include <unordered_map>
#define ll long long
#define ld long double
using namespace std;
unordered_map<ll,ll> x,y;
ll i, j, n, m, k, p, q, a[300005], b[300005];
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> n;
for (i = 1; i <= n; i++)
{
cin >> a[i] >> b[i];
x[a[i]]++;
y[b[i]]++;
}
for (i = 1; i <= n; i++)
m += (x[a[i]] - 1)*(y[b[i]] - 1);
cout << m << endl;
return 0;
}
