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.*;

public class Main{
	static public void  main(String[] args){
		Scanner scan = new Scanner(System.in);

		int A = scan.nextInt();
		int B = scan.nextInt();

		int x1 = A + A -1;
		int x2 = A + B ;
		int x3 = B + B -1;
		int r1 = (x1 > x2)? x1: x2;
		int ret = r1 > x3? r1 : x3;

		System.out.println(ret);

	}
}
