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-----
5 3

-----Sample Output-----
9

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

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