import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		while(sc.hasNext()){
			int a=sc.nextInt();
			int b=sc.nextInt();
			if(a<b) System.out.println(b-2);
			else System.out.println(2000000000-b-1);
		}
	}
}