#include <bits/stdc++.h> using namespace std; const int N = 1e5 + 5; int main() { int n, k = 0; cin >> n; vector<int> a(3); for(int i = 0; i < n * 2; i++) { int x, y; cin >> x >> y; x = max(1, min(n, x)); y = max(1, min(2, y)); a[y]++; } int x1 = a[1] - n; int x2 = a[2] - n; k += abs(x1) + abs(x2); cout << k; }