import java.io.*;
import java.util.*;

public class Solution {

    public static void main(String[] args) {
        Scanner s=new Scanner(System.in);
        long n=s.nextLong();
        long m=s.nextLong();
        long sum=0L;
        long a=0L;
        if(m>n)
            {
                 a=m-1;
                sum=a+(n-1)*m;
            System.out.println(sum);
            
        }
        else if(n>m)
            {
            if(m>1)
                {
                a=n-1;
                sum=a+m*n;
                System.out.println(sum);
            }
            else
                {
                a=n-1;
                sum=a+(m-1)*n;
                System.out.println(sum);
            }
        }
        else
            {
                a=n-1;
                sum=a+(n-1)*m;
            System.out.println(sum);
            
        }
    }
}