#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define fr first
#define sc second
#define clr(a, x) memset(a, x, sizeof(a))
#define dbg(x) cout<<"("<<#x<<"): "<<x<<endl;
#define printvector(arr) for (auto it = arr.begin(); it != arr.end(); ++it) cout<<*it<<" "; cout<<endl;
#define all(v) v.begin(), v.end()
#define lcm(a, b) (a * b)/__gcd(a, b)
#define int long long int
#define printvecpairs(vec) for(auto it: vec) cout<<it.fr<<' '<<it.sc<<endl;
#define endl '\n'
#define float long double
const int MOD = 1e9 + 7;
const int INF = 2e15;
const int MAXN = 1e5 + 5;
map<int, int> cntx, cnty;
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
#endif
int n;
cin>>n;
vector<pair<int, int>> v;
for(int i = 0;i<n;i++){
int t1, t2; cin>>t1>>t2;
v.pb({t1, t2});
cntx[t1]++;
cnty[t2]++;
}
int ans = 0;
for(auto it: v){
ans += (cntx[it.fr]-1) * (cnty[it.sc]-1);
}
cout<<ans<<endl;
return 0;
}
