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

public class Solution {
    
    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        Scanner in = new Scanner(System.in);
       
        long n = in.nextInt();
        long m = in.nextInt();
        //compute(n,m);
        long ans = Math.min(n - 1 + n * (m - 1), m - 1 + m * (n - 1));
        System.out.println(ans + "");
    }
}