Problem:
Score : 100 points

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

Solution in PHP7 (7.0.15) (judge verdict: Accepted)

<?php
// Your code here!
fscanf(STDIN,"%d %d",$a,$b);

$sum = 0;

for($i=0;$i<2;$i++){
    if($a > $b){
        $sum += $a;
        $a -= 1;
    }elseif($a < $b){
        $sum += $b;
        $b -= 1;
    }else{
        $sum += $a;
        $a -= 1;
    }
}

echo $sum;
?>