// goodwincommaderek@gmail.com
import java.util.Scanner;

public class trianglesofasquare_dg_ac {
    static final int SIDE_LEN = 2024;
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int x1 = in.nextInt();
        int y1 = in.nextInt();
        int x2 = in.nextInt();
        int y2 = in.nextInt();

        int possible = 4;
        if (x1 == 0 || x1 == SIDE_LEN) possible--;
        if (x2 == 0 || x2 == SIDE_LEN) possible--;
        if (y1 == 0 || y1 == SIDE_LEN) possible--;
        if (y2 == 0 || y2 == SIDE_LEN) possible--;
        System.out.println(possible);
    }
}