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) {
	Scanner tc = new Scanner (System.in);
	int a,b;
	a=tc.nextInt();
	b=tc.nextInt();
	if(a>b) {
		System.out.println(a*2-1);
	}
	if(b>a) {
		System.out.println(b*2-1);
	}
	if(a==b) {
		System.out.println(a+b);
	}
}
}
