#include <bits/stdc++.h>
#define int long long
#define pb push_back
#define fs first
#define sc second
using namespace std;
signed main() {
int n;
cin >> n;
vector<pair<int, int>> p(n);
vector<int> xs, ys;
for(int i = 0; i < n; i++){
int a, b;
cin >> a >> b;
p[i] = {a, b};
xs.pb(a);
ys.pb(b);
}
sort(xs.begin(), xs.end());
xs.erase(unique(xs.begin(), xs.end()), xs.end());
sort(ys.begin(), ys.end());
ys.erase(unique(ys.begin(), ys.end()), ys.end());
unordered_map<int, int> nx, ny;
for(int i = 0; i < xs.size(); i++) nx[xs[i]] = i;
for(int i = 0; i < ys.size(); i++) ny[ys[i]] = i;
vector<int> cx(xs.size() + 1, 0), cy(ys.size() + 1, 0);
for(auto [x, y]:p){
int xc = nx[x], yc = ny[y];
cx[xc]++;
cy[yc]++;
}
int ans = 0;
for(auto [x, y] : p){
int xc = nx[x], yc = ny[y];
ans += (cx[xc] - 1) * (cy[yc] - 1);
}
cout << ans << endl;
}
