# include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
typedef long long ll;
#define pii pair<int,int>
const int N = 3e5 + 5;
const int INF = 1e9;
const ll mod = 1e9+7;
int x[N],y[N];
map<int,int>row,col;
int n;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
//freopen("triangles.in","r",stdin);
//freopen("triangles.out","w",stdout);
cin>>n;
for(int i = 1;i<=n;i++){
cin>>x[i]>>y[i];
row[x[i]]++;
col[y[i]]++;
}
ll ans = 0;
for(int i = 1;i<=n;i++){
ans += (1LL * (row[x[i]]-1) * (col[y[i]]-1));
}
cout<<ans<<endl;
}
