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.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ABC124A
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] input = Console.ReadLine().Split(' ');//キーボードからスペース区切りで数値を入力する
            int A = int.Parse(input[0]);//はじめの数値を整数型の変数Ａに代入します
            int B = int.Parse(input[1]);//二番目の数値を整数型の変数Ｂに代入します

            int ans = 0;//答えを入れる整数型の変数ansを用意します。

            if (A > B) //もしもＡが大きいなら、ansにＡを入れておく。　Ａを1だけ小さくする
            {
                ans = A;
                A = A - 1;
            } //もしもＢが大きいなら、ansにＢを入れておく　Ｂを1だけ小さくする
            else
            {
                ans = B;
                B = B - 1;
            }

            if (A > B)//もう一回　Ａが大きいならansにＡを加える
            {
                ans = ans + A;
            }
            else//Ｂが大きいならansにＢを加える
            {
                ans = ans + B;
            }
            Console.WriteLine(ans);//答えを出力する
        }
    }
}