#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  int x, y, a = -1e7, b = -1e7, c = 1e7, d = 1e7;
  cin >> n;
  while (n--) {
    cin >> x >> y;
    a = max(a, x + y + 1);
    d = min(d, x + y - 1);
    b = max(b, y - x + 1);
    c = min(c, y - x - 1);
  }
  cout << (a - d) + (b - c);
}
