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: Accepted)

using System;
using System.Linq;

namespace AButtons
{
    class Program
    {
        static void Main(string[] args)
        {
            // 入力の取得
            var inputs = Console.ReadLine().Split().Select(int.Parse).ToArray();
            var a = inputs[0];
            var b = inputs[1];

            var sum = Math.Max(a, b);
            if (a < b) sum += Math.Max(a, b - 1);
            else sum += Math.Max(a - 1, b);

            // 解答の出力
            Console.WriteLine(sum);
        }
    }
}