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;

class Main {
    public static void main(String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int A = sc.nextInt();
    	int B = sc.nextInt();
    	int sum = 0;

    	for(int i =0 ;i<2;i++){

    		if(A>B){
    			sum += A;
    			A--;
    		}else{
    			sum += B;
    			B--;
    		}

    		    	}

    	System.out.println(sum);



}

}