#include <bits/stdc++.h>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cstring>
#include <chrono>
#include <complex>
#define endl "\n"
#define ll long long int
#define vi vector<int>
#define vll vector<ll>
#define vvi vector < vi >
#define pii pair<int,int>
#define pll pair<long long, long long>
#define mod 1000000007
#define inf 1000000000000000001;
#define all(c) c.begin(),c.end()
#define mp(x,y) make_pair(x,y)
#define mem(a,val) memset(a,val,sizeof(a))
#define pb push_back
#define f first
#define s second
#define pi 3.141592653589793238
using namespace std;
ll gcd( ll a, ll b )
{
if(b==0)
{
return a;
}
else
{
return gcd( b, a%b );
}
}
ll lcm (ll a, ll b)
{
return (a*b)/gcd(a,b);
}
ll power(ll a, ll b) //a is base, b is exponent
{
if(b==0)
return 1;
if(b==1)
return a;
if(b%2 == 1)
return (power(a,b-1)*a)%mod;
ll q = power(a,b/2);
return (q*q)%mod;
}
map<int,int> x;
map<int,int> y;
int main()
{
std::ios::sync_with_stdio(false);
int n;
cin>>n;
vector<pii> v;
set<int> se;
for(int i =1;i<=n;i++){
int a,b;
cin>>a>>b;
x[a]++;
y[b]++;
v.pb(mp(a,b));
se.insert(a);
}
int ans = 0;
for(auto p:v){
int lol = x[p.first]-1;
lol *= (y[p.second]-1);
ans+=lol;
}
cout<<ans<<endl;
return 0;
}
//Hello, this is a snippet.
