import java.util.*;
import java.math.*;
import java.io.*;
public class Main{
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		if(a < b) {
			System.out.println(a - 1);
		}
		else {
			System.out.println(2000000000 - a);
		}
	}
 }