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;

class Program
{
  static void Main(string[] args)
  {
    string[] nums = Console.ReadLine().Split(' ');
    int N1 = int.Parse(nums[0]);
    int N2 = int.Parse(nums[1]);
    int Sum = 0;
    
    if(N1 > N2)
    {
      Sum += N1;
      N1 -= 1;
      if(N1 > N2) Sum += N1;
      else Sum += N2;
    }
    else
    {
      Sum += N2;
      N2 -= 1;
      if(N1 < N2) Sum += N2;
      else Sum += N1;
    }  
    Console.Write(Sum);
  }
}