101240: [AtCoder]ABC124 A - Buttons

Problem Statement

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.

Sample Input 1

5 3

Sample Output 1

9

You can get $5 + 4 = 9$ coins by pressing the button of size $5$ twice, and this is the maximum result.

Sample Input 2

3 4

Sample Output 2

7

Sample Input 3

6 6

Sample Output 3

12