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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;

class Program{

  static int ans;
  static int a;
  static int b;

  static int Main() {

    string[] nyu = Console.ReadLine().Split(' ');
    a = int.Parse(nyu[0]);
    b = int.Parse(nyu[1]);

    // ここまで入力

    int[] score = new int[3];
    score[0] = a * 2 - 1;
    score[1] = b * 2 - 1;
    score[2] = a + b;

    ans = score.Max();

    Console.WriteLine("{0}", ans);

    return 0;
  }

}