//Bismillahi-rahmani-rahim
#include <bits/stdc++.h>
#include <algorithm>
using namespace std;
typedef long long ll;
typedef map <int, int> mii;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
const int inf=1e9;
#define azdar priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>>
#define Lebap ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define mp make_pair
#define pb push_back
#define pf push_front
#define pk pop_back
#define ff first
#define ss second
#define all(x) x.begin(), x.end()
//#include <conio.h>
#include <climits>
const int N = 1e6+9;
map<ll,int> X,Y;
ll n, x[N],y[N],ans=0;
int main(){
Lebap;
cin>>n;
for(int i=1;i<=n;i++){
cin>>x[i];
cin>>y[i];
X[x[i]]++;
Y[y[i]]++;
}
for(int i=1;i<=n;i++){
ans += (X[x[i]]-1)*(Y[y[i]]-1);
}
cout << ans;
return 0;
}
