import java.util.Scanner;

public class PaperCutting {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        long n = s.nextLong();
        long m = s.nextLong();
        long a = (n-1)+(n*(m-1));
        long b = (m-1)+(m*(n-1));
        System.out.println(Math.min(a, b));
    }
}