// 2023 IUSB Programming Competition
// Round 1 Problem 4
// Knight Movement
// Solution by Liguo Yu

#include <iostream>
using namespace std;

bool oneStep(int x1, int y1, int x2, int y2);
    
int main()
{
  int x1, y1, x2, y2;
  cin >> x1 >> y1 >> x2 >> y2;
  
  int steps;
        
  if(x1==x2 && y1==y2) steps = 0;
  else if (oneStep(x1, y1, x2, y2)) steps = 1;
  else if (oneStep(x1, y1, x2+1, y2+2)) steps = 2;
  else if (oneStep(x1, y1, x2+1, y2-2)) steps = 2;
  else if (oneStep(x1, y1, x2-1, y2+2)) steps = 2;
  else if (oneStep(x1, y1, x2-1, y2-2)) steps = 2;
  else if (oneStep(x1, y1, x2+2, y2+1)) steps = 2;
  else if (oneStep(x1, y1, x2+2, y2-1)) steps = 2;
  else if (oneStep(x1, y1, x2-2, y2+1)) steps = 2;
  else if (oneStep(x1, y1, x2-2, y2-1)) steps = 2;
  else steps = -1;
        
  if(steps != -1) cout << steps << endl;
  else cout << ">2" << endl;
        
  return 0;
}
    
bool oneStep(int x1, int y1, int x2, int y2)   
{
  if((x2 == x1+1 && y2 == y1+2) || (x2 == x1+2 && y2 == y1+1) || (x2 == x1+1 && y2 == y1-2) || (x2 == x1+2 && y2 == y1-1) || (x2 == x1-1 && y2 == y1-2) || (x2 == x1-2 && y2 == y1-1) || (x2 == x1-1 && y2 == y1+2) || (x2 == x1-2 && y2 == y1+1))
    return true;
  else return false;
}