#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ld long double
#define show(x,y) cout << y << " " << #x << endl;
#define show2(x,y,i,j) cout << y << " " << #x << " " << j << " " << #i << endl;
#define show3(x,y,i,j,p,q) cout << y << " " << #x << " " << j << " " << #i << " " << q << " " << #p << endl;
#define show4(x,y) for(auto it:x) cout << it << " "; cout << #y << endl;
typedef pair<long long,long long>pii;
void solve(){
int n;
cin >> n;
pii arr[n];
map<int,int>hori;
map<int,int>vert;
for(int x=0;x<n;x++){
cin >> arr[x].first >> arr[x].second;
hori[arr[x].first]++;
vert[arr[x].second]++;
}
int counter=0;
for(int x=0;x<n;x++){
int hold=hori[arr[x].first]-1;
int hold2=vert[arr[x].second]-1;
counter+=(hold*hold2);
}
cout << counter;
}
int32_t main(){
ios::sync_with_stdio(0);
cin.tie(0);
int t=1;
//cin >> t;
while(t--){
solve();
}
}
