import java.util.Scanner;

class Test {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		String str1 = in.next();
		String str2 = in.next();
		int A = Integer.parseInt(str1);
		int B = Integer.parseInt(str2);
		
		if(A > B) {
			int m = 2000000000 - A;
			int n = A - B - 1;
			System.out.println(m + n);
		}
		if(A < B) {
			System.out.println(A - 1);
		}
	}
}