#include <bits/stdc++.h>
#define pb push_back
#define pf push_front
using namespace std;
#define F first
#define S second
typedef long long ll;
#define pii pair <int, int>
#define pll pair <ll, ll>
typedef long double ld;
const ll N = 3 * 1e5 + 100, M = 500 + 10, len = 315, inf = 1e18;
const ll mod = 998244353;
ll um(ll a, ll b){
return (1LL * a * b) % mod;
}
ll subr(ll a, ll b){
return ((1LL * a - b) % mod + mod) % mod;
}
ll bp(ll x, ll step){
ll res = 1;
while(step){
if(step & 1) res = um(res, x);
x = um(x, x);
step /= 2;
}
return res;
}
ll inv(ll x){
return bp(x, mod - 2);
}
ll a[N], b[N];
int main() {
//ios_base::sync_with_stdio(false);
//cin.tie(nullptr);
//cout.tie(nullptr);
ll n;
cin >> n;
map<int, int> mp, mp1;
for(ll i = 0; i < n; i++){
cin >> a[i] >> b[i];
mp[a[i]]++;
mp1[b[i]]++;
}
ll ans = 0;
for(ll i = 0; i < n; i++){
ans += (mp[a[i]] - 1) * (mp1[b[i]] - 1);
}
cout << ans;
return 0;
}
