#include "bits/stdc++.h"
using namespace std;
#define int long long
#define ll long long
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define pob pop_back
#define pof pop_front
#define sz size
#define fr front
#define bc backn
#define pii pair<int,int>
#define all(x) x.begin() , x.end()
#define cmin(a, b) a = min(a , b)
#define cmax(a, b) a = max(a, b)
#define mems(arr , a) memset(arr , a , sizeof arr)
#define each(i , arr) for(auto &i : arr)
const int MOD = 1e9 + 7;
const int INF = 1e18;
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t;
t = 1;
// cin >> t;
while(t--){
int n; cin >> n;
int x[n] , y[n];
map<int , int> cntx , cnty;
for(int i = 0; i < n; i++){
cin >> x[i] >> y[i];
cntx[x[i]]++ , cnty[y[i]]++;
}
int ans = 0;
for(int i = 0; i < n; i++){
ans += (cntx[x[i]]-1) * (cnty[y[i]]-1);
}
cout << ans << '\n';
}
}
