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(args) {
  	var max = 0;
	var input = args.split(/\s/);
  	var a = input[0] * 1;
  	var b = input[1] * 1;
  	for (var i = 0; i <= 2; i++) {
    	if (a >= b) {
        	max += a;
          	a--;
        }
      	if (a < b) {
        	max += b;
          	b--;
        }
    }
  	console.log(max);
}

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