import java.util.Scanner;
public class No643 {

	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		int x=Integer.parseInt(sc.next());
		int y=Integer.parseInt(sc.next());
		if(x==y) {
			System.out.println(0);
		}else if(x==0) {
			System.out.println(2);
		}else if(y==0) {
			System.out.println(1);
		}else if(x==-y){
			System.out.println(3);
		}else{
			System.out.println(-1);
		}
	}

}