//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define ll long long
#define F first
#define S second
#define ull unsigned long long
#define db double
#define ldb long double
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define ordered_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
#define all(x) x.begin(), x.end()
const int mod = 1e9 + 7;
const int N = 500001;
using namespace std;
using namespace __gnu_pbds;
ll n, m, a, b, c, d, e, cnt[3][N];
pair <ll, ll> p[N];
ll gcd (ll a, ll b){while (a > 0 && b > 0){if (a >= b){a %= b;}else{b %= a;}}return a + b;}
ll binpow (ll a, ll b){
a %= mod;if (b == 0){return 1;}
else if (b % 2 == 1){
return binpow (a, b - 1) % mod * a % mod;
}
else{
ll t = binpow (a, b / 2) % mod;
return t * t % mod;
}
}
signed main (){
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin >> n;
for (int i = 1; i <= n; i++){
cin >> p[i].first >> p[i].second;
cnt[1][p[i].first]++;
cnt[2][p[i].second]++;
}
for (int i = 1; i <= n; i++){
a += (cnt[1][p[i].first] - 1) * (cnt[2][p[i].second] - 1);
}
cout << a;
}
