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)
        {

            {
                var word = Console.ReadLine().Split();
                int a = int.Parse(word[0]);
                int b = int.Parse(word[1]);
                int max = 0;
                for (int i = 0; i < 2; i++)
                {
                    if (a < b)
                    {
                        max += b;
                        b--;
                        continue;
                    }
                     if (b <= a)
                    {
                        max += a;
                        a--;
                        continue;
                    }
                }
                    Console.WriteLine(max);
                    Console.ReadKey();



                }
            }
        }
    }