#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vb = vector<bool>;
using vvb = vector<vb>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vc = vector<char>;
using vvc = vector<vc>;
using vs = vector<string>;
const ll mod = 1e9 + 7,inf = 1e18;
#define pb push_back
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
void setIO()
{
fast;
}
int main()
{
setIO();
int n;
cin>>n;
vvi p(n,vi(2));
map<int,int>x,y;
for (int i = 0;i<n;i++)cin>>p[i][0]>>p[i][1],x[p[i][0]]++,y[p[i][1]]++;
ll ans = 0;
for (int i = 0;i<n;i++)
ans += 1ll * (x[p[i][0]] - 1) * 1ll * (y[p[i][1]] - 1);
cout<<ans;
return 0;
}
