/*
ID: samikgo1
TASK:
LANG: C++
*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;
#define all(x) x.begin(),x.end()
#define allr(x) x.rbegin(),x.rend()
#define f first
#define s second
//#define x first
//#define y second
const int INF = INT32_MAX;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
// freopen("measurement.in","r",stdin);
// freopen("measurement.out","w",stdout);
ll n;
cin >> n;
vector<pll> points(n);
for(pll&i:points)cin>>i.f>>i.s;
unordered_map<ll,ll> x_axis;
unordered_map<ll,ll> y_axis;
ll ans = 0;
for (pll &i: points) {
x_axis[i.first]++;
y_axis[i.second]++;
}
for (pll &i: points) {
ans+=(x_axis[i.first]-1)*(y_axis[i.second]-1);
}
cout << ans;
}
