#include<iostream> #include<map> using namespace std; #define int long long int a[300001],b[300001]; map<int,int> x,y; signed main(){ int n,i,rasp=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++){ rasp+=(x[a[i]]-1)*(y[b[i]]-1); } cout<<rasp; }