#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int x1, y1;
  cin >> x1 >> y1;
  int x2, y2;
  cin >> x2 >> y2;
  int ans = 0x3f3f3f3f;
  for (int i = -1; i <= 1; i++) {
    for (int j = -1; j <= 1; j++) {
      if (i == 0 && j == 0) {
        continue;
      }
      ans = min(ans, abs(x1 - (x2 + i)) + abs(y1 - (y2 + j)));
    }
  }
  cout << 2 * ans + 8;
}
