#include<bits/stdc++.h>
#define fast ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL)
#define pb push_back
#define F first
#define S second
#define int long long
using namespace std;
const int N = 1e6 + 5, MOD = 1e9 + 7;
int n, x[N], y[N];
void solve(){
cin >> n;
map<int, int> cmp, cmp1;
for(int i = 0; i < n; ++i){
cin >> x[i] >> y[i];
cmp[y[i]]++;
cmp1[x[i]]++;
}
int ans = 0;
for(int i = 0; i < n; ++i)
ans += (cmp[y[i]] - 1) * (cmp1[x[i]] - 1);
cout << ans << '\n';
}
int32_t main(){
fast;
int t = 1;
// cin >> t;
while(t--)
solve();
return 0;
}
