Problem:
Score : 100 points

Problem Statement

There are two buttons, one of size A and one of size B.

When you press a button of size X, you get X coins and the size of that button decreases by 1.

You will press a button twice. Here, you can press the same button twice, or press both buttons once.

At most how many coins can you get?

Constraints

All values in input are integers.

3 \leq A, B \leq 20

Input

Input is given from Standard Input in the following format:

A B

Output

Print the maximum number of coins you can get.

Sample Input 1

5 3

Sample Output 1

9

You can get 5 + 4 = 9 coins by pressing the button of size 5 twice, and this is the maximum result.

Sample Input 2

3 4

Sample Output 2

7

Sample Input 3

6 6

Sample Output 3

12

Solution in C# (Mono 4.6.2.0) (judge verdict: Wrong Answer)

using System;

namespace Atcoder
{
    class Program
    {
        static void Main(string[] args)
        {


            //テンプレート
            //// 整数の入力
            //int a = int.Parse(Console.ReadLine());
            //// スペース区切りの整数の入力
            //string[] input = Console.ReadLine().Split(' ');
            //int b = int.Parse(input[0]);
            //int c = int.Parse(input[1]);
            //// 文字列の入力
            //string s = Console.ReadLine();
            ////出力
            //Console.WriteLine(a + b + c + " " + s);


            string[] input = Console.ReadLine().Split(' ');
            int a = int.Parse(input[0]);
            int b = int.Parse(input[1]);

            int get_coins;

            if (b >= a)
                get_coins = 2 * b - 1;
            else
                get_coins = 2 * a - 1;

            Console.WriteLine(get_coins);
 //           Console.ReadLine();

        }

    }
}