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) {
		// TODO 自動生成されたメソッド・スタブ
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);



	}
}