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

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 sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        int cuts_ct = 0;

        if (n == 1) {
            cuts_ct = m - 1;
        } else if (m == 1) {
            cuts_ct = n - 1;
        }

        int cut1 = (n - 1) + n * (m - 1);
        int cut2 = (m - 1) + m * (n - 1);
        cuts_ct = cut1 < cut2 ? cut1 : cut2;
         System.out.print(cuts_ct);
    }
}