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 stdIn = new Scanner(System.in);

	int a = stdIn.nextInt();
	int b = stdIn.nextInt();
	int coin = 0;
	
	for (int i = 0; i < 2; i++) {
		if (a >= b) {
			coin += a;
			a--;
		} else {
			coin += b;
			b--;
		}
	}
	
	System.out.println(coin);
	
	}
}