using System;
using System.Linq;
using System.Numerics;

namespace Bounce
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] input = new int[2];
            input = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
            BigInteger[,] matrix = new BigInteger[input[0], input[1]];
            int n = input[0];
            int m = input[1];
            //declare matrix
            string direction = "downRight";
            int startingRow = 0;
            int startingCol = 0;
            BigInteger sum = 1;
            //fill matrix with correct vallues
            for (int row = 0; row < n; row++)
            {
                for (int col = 0; col < m; col++)
                {
                    matrix[row, col] = (int)Math.Pow(2, row + col);
                }
            }
            while (true)
            {

                if (direction == "downRight")
                {
                    startingRow++;
                    startingCol++;
                    sum += matrix[startingRow, startingCol];
                    if (startingRow == n-1 || startingCol == m-1)
                    {
                        if (startingRow == n-1)
                        {
                            direction = "rightUp";
                        }
                        else
                        {
                            direction = "downLeft";
                        }
                    }
                }
                if (direction == "rightUp")
                {
                    startingRow--;
                    startingCol++;
                    sum += matrix[startingRow, startingCol];

                    if (startingRow == 0 || startingCol == m-1)
                    {
                        if (startingCol == m-1)
                        {
                            direction = "upLeft";//To Do: direction = "upRight";
                        }
                        else
                        {
                            direction = "downRight"; //To Do:  direction = "upLeft";
                        }
                    }
                }
                if (direction == "downLeft")
                {
                    startingRow++;
                    startingCol--;
                    sum += matrix[startingRow, startingCol];

                    if (startingRow == n - 1 || startingCol == 0)
                    {
                        if (startingCol == 0)
                        {
                            direction = "downRight";
                        }
                        else
                        {
                            direction = "upLeft";
                        }
                    }
                }
                if (direction == "upLeft")
                {
                    startingRow--;
                    startingCol--;
                    sum += matrix[startingRow, startingCol];

                    if (startingRow == 0 || startingCol == 0)
                    {
                        if (startingCol == 0)
                        {
                            direction = "upRight";
                        }
                        else
                        {
                            direction = "downLeft";
                        }
                    }

                }

                if (direction == "downLeft")
                {
                    startingRow++;
                    startingCol--;
                    sum += matrix[startingRow, startingCol];

                    if (startingRow == n-1 || startingCol == 0)
                    {
                        if (startingCol == 0)
                        {
                            direction = "downRight";
                        }
                        else
                        {
                            direction = "upLeft";
                        }
                    }

                }
                if (direction == "upRight")
                {
                    startingRow--;
                    startingCol++;
                    sum += matrix[startingRow, startingCol];

                    if (startingRow == 0 || startingCol == m-1)
                    {
                        if (startingRow == 0)
                        {
                            direction = "downRight";
                        }
                        else
                        {
                            direction = "upLeft";
                        }
                    }

                }
                if (direction == "upRight" || direction == "upLeft" || direction == "downLeft"  || direction == "downRight" || direction == "rightUp" ||  direction == "downLeft")
                {
                    if (startingRow == 0 && startingCol == 0 || startingRow == 0 && startingCol == m-1
                        || startingRow == n-1 && startingCol == 0 || startingRow == n - 1 && startingCol == m - 1)
                    {
                        break;
                    }
                }
                if (direction == "sss")
                {
                    break;
                }
            }
            /*
            Console.WriteLine($"row-{startingRow} and col-{startingCol}");
            Console.WriteLine(direction);
            Print(matrix);
            */
            Console.WriteLine(sum);
        }

        static void Print(int[,] matrixToPrint)
        {
            for (int row = 0; row < matrixToPrint.GetLength(0); row++)
            {
                for (int col = 0; col < matrixToPrint.GetLength(1); col++)
                {
                    Console.Write(matrixToPrint[row, col] + " ");
                }
                Console.WriteLine();
            }
        }
    }
}