import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    static Scanner sc = new Scanner(System.in);
  
   
    static int i(){
        return sc.nextInt();
    }
	
	static int[] ia(int n){                                     //integer array urf ia()
      int arr[] = new int[n];
        
        for(int i=0;i<n;i++)
        arr[i] = i();
        return arr;
    }
	static long l(){
        return sc.nextLong();
    }
    static String s(){
        return sc.nextLine();
    }
	
    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        long n = l();
        long m = l();
        
         
        long b = Math.max(n,m);
        long s = Math.min(n,m);
        
        System.out.print(b-1+b*(s-1));
    }
}