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 {
	void run() {
		Scanner scan = new Scanner(System.in);
		int a = scan.nextInt();
		int b = scan.nextInt();
		if (a == b)
			System.out.println(a * 2);
		else if (a < b)
			System.out.println(b + (b - 1));
		else
			System.out.println(a + (a - 1));
	}
    public static void main(String[] args) {
    	new Main().run();
    }
}
