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)
        {
    　　    int a,b,c;
            string[] str = Console.ReadLine().Split(' ');
            a = int.Parse(str[0]);
            b = int.Parse(str[1]);
            c = 0;
            if (a < b)
            {
              c += b;
              b--;
              if (a <= b)
              {
                c += b;
              }
              else
              {
                c += a;
              }
            }
            else if (a > b)
            {
              c += a;
              a--;
              if (a <= b)
              {
                c += b;
              }
              else
              {
                c += a;
              }
            }
            else
            {
              c = a + b;
            }
              
            
            Console.WriteLine(c);
        }
 }