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.

Examples

Input

5 3


Output

9


Input

3 4


Output

7


Input

6 6


Output

12
import java.util.Scanner;

public class Main
{

	public static void main(String[] args)
	{
		Scanner sc = new Scanner(System.in);

		int a = Integer.parseInt(sc.next());
		int b = Integer.parseInt(sc.next());
		int answer = (a - b > 0) ? a + (a - 1) :
					 (b - a > 0) ? b + (b - 1) :
						 		   a + b;

		System.out.println(answer);
		sc.close();
	}
}