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.*; 

class Main{
public static void main(String[] args){
	Scanner sc=new Scanner(System.in);
        int a=sc.nextInt();
        int b=sc.nextInt();
		int ans=0;
		ans+=Math.max(a,b);
  		if(a<=b){
          b--;
        }else{
          a--;
        }
  		ans+=Math.max(a,b);
  		
    
    	System.out.println(ans);
    }
}