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)

'use strict'
let lines = []
let reader = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
})
reader.on('line', function(line) {
  lines.push(line.split(' '))
})
reader.on('close', function(line) {
  let ans = 0
  let a = lines[0]
  let b = lines[1]
  if (a > b) {
    ans += a
    a--
  } else {
    ans += b
    b--
  }
  if (a > b) {
    ans += a
  } else {
    ans += b
  }
  console.log(ans) 
})