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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

function Main(input) {
  tmp = input.split(" ");
  // convert string from integer using "parseInt"
  var a = parseInt(tmp[0], 10);
  var b = parseInt(tmp[1], 10);

  var num1 = a + (a - 1);
  var num2 = a + b;
  var num3 = b + (b - 1);

  return Math.max(num1, num2, num3);
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));