import java.util.Scanner;

public class Main {


    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
        if(a==1||b==1){
            System.out.println(1);
        } else {
        long[][] matrix = new long[a][b];
        long num = 1;
        long sum = 1;



            for (int i = 0; i < matrix.length; i++) {
                for (int j = 0; j < matrix[matrix.length - 1].length; j++) {
                    matrix[i][j] = num;
                    num *= 2;
                }
                num = matrix[i][1];
            }

            int i = 0;
            int j = 0;
            int c = 1;
            int d = 1;
            while (true) {
                if (i == a - 1) {
                    c *= -1;
                }
                if (i == 0) {
                    c = 1;
                }
                i = i + c;
                if (j == b - 1) {
                    d *= -1;
                }
                if (j == 0) {
                    d = 1;
                }
                j = j + d;
                sum += matrix[i][j];

                if ((i == 0 && j == 0) || (i == a - 1 && j == b - 1) || (i == a - 1 && j == 0) || (j == b - 1 && i == 0)) {
                    System.out.println(sum);
                    break;
                }
            }
        }



    }
}