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;

class Program
{
    static int Main()
    {
        int a, b;
        string[] in1= Console.ReadLine().Split(' ');
        a = int.Parse(in1[0]);
        b = int.Parse(in1[1]);
        if (a == b)
            Console.WriteLine((2 * a).ToString("d"));
        else
            Console.WriteLine((2 * (a > b ? a : b) - 1).ToString("d"));
        return 0;
    }
}