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: Wrong Answer)

using System;
class Program
{
    static void Main(string[] args)
    {
        string[] str = Console.ReadLine().Split(' ');//2つ以上のスペース区切り入力の取得
        int A = int.Parse(str[0]);  //数値で受け取りたい場合は変換する
        int B = int.Parse(str[1]);
        int C = 0;
        for (int i=0; i < 2; i++)
        {
            if(A < B)
            {
                C = C + B;
            }else
            {
                C = C + A;
            }
        }
        Console.WriteLine(C);
    }
}