package no333;

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		long b = sc.nextLong();
		long ans = 0;
		long min = Math.min(a, b);
		long max = Math.max(a, b);
		if (min > 1 && isKadomatsuSequence(a, b, 1)) {
			ans += Math.min(a, b) - 1;
		}
		if(min + 1 < max && isKadomatsuSequence(a, b, a+1)) {
			ans += max - min - 1;
		}
		if (max < 2000000000 && isKadomatsuSequence(a, b, 2000000000)) {
			ans += 2000000000 - max;
		}
		System.out.println(ans);
	}
	
	public static boolean isKadomatsuSequence(long a,long b,long c) {
		if (a == b || b == c) {
			return false;
		}
		return b < a && b < c || b > a && b > c;
	}

}