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.Text;

namespace AtcoderTest.BeginnerContest124
{
    class A
    {
        public static void Main()
        {
            string line = Console.ReadLine();
            var str = line.Split(' ');
            int A = int.Parse(str[0]);
            int B = int.Parse(str[1]);

            int sum = 0;
            for(int i = 0; i < 2; i++)
            {
                if (A >= B)
                {
                    sum += A;
                    A--;
                }
                else
                {
                    sum += B;
                    B--;
                }
            }

            Console.WriteLine(sum);

        }
    }
}