import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import static java.lang.System.in;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        String[] inputs = reader.readLine().split(" ");
        int A = Integer.parseInt(inputs[0]);
        int B = Integer.parseInt(inputs[1]);
        if(A<B) {
            System.out.println((A-1) + (B-A-1));
        } else {
            System.out.println( (2000000000-A) + (A-B-1));
        }
    }
}