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

import java.util.Scanner;

public class round1_p4
{   
    public static void main(String[] args)
    {
        Scanner input = new Scanner(System.in);
        int x1 = input.nextInt();
        int y1 = input.nextInt();
        int x2 = input.nextInt();
        int y2 = input.nextInt();
        
        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) System.out.println(steps);
        else System.out.println(">2");
    }
    
    public static boolean 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;
    }
}