#include <bits/stdc++.h> using namespace std; int main() { int n; scanf("%d", &n); map <int, int> xs; map <int, int> ys; map < pair <int, int>, int > zs; long long ans = 0; for (int i = 0; i < n; i++) { int x, y; scanf("%d %d", &x, &y)...