#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define vec vector
#define pll pair<ll,ll>
#define fr first
#define sc second
ll n,ans=0;
vec<pll>a;
map<ll,ll>mx,my;
signed main(){ // CELONA IS MY GF <3
ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
cin>>n;a.resize(n);
for(auto&el:a){
cin>>el.fr>>el.sc;
auto [x,y]=el;
if(mx.find(x)==mx.end())mx[x]=0;mx[x]++;
if(my.find(y)==my.end())my[y]=0;my[y]++;
}
for(auto[x,y]:a){
ll xx=mx[x]-1,yy=my[y]-1;
ans+=xx*yy;
}
cout<<ans;return 0;
}
