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;
					
public class Program
{
	public static void Main()
	{
		int a;
		int b;
        string[] str = Console.ReadLine().Split(' ');//2つ以上のスペース区切り入力の取得
        a = int.Parse(str[0]);  //数値で受け取りたい場合は変換する
        b = int.Parse(str[1]);
		int res;
		if(a==b){
			res = a*2;
		}else{
		res = a < b ? b*2 - 1: a*2 - 1;
		}
		
		Console.WriteLine(res);
	}
}