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: Wrong Answer)

list($a, $b) = getLineExploded(' ');


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

println($ret);




function println($str)
{
    echo $str . "\n";
}

function sprintlnFormat($format, $str)
{
    println(sprintf($format, $str));
}

function getOneLine()
{
    $str = trim(fgets(STDIN));
    return $str;
}

function getLineExploded($delimiter = ' ')
{
    $str = getOneLine();
    $ret = explode($delimiter, $str);
    return $ret;
}