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: Runtime Error)

function main(input) {
  const [A, B] = input.split(" ").map(i => parseInt(i));
  let max = 0;
  if (max < A + A - 1) {
    max = A + A - 1;
  }
  if (max < A + B) {
    max = A + B - 1;
  }
  if (max < B + B - 1) {
    max = B + B - 1;
  }
  console.log(max);
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));