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 scanner = new Scanner (System.in);
      	int A = scanner.nextInt();
      	int B = scanner.nextInt();
      	int sum = Math.max(A,B);
      	if (A > B) A--;
        else B--;
      	sum += Math.max(A,B);
      	System.out.println(sum);
    }
}