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: Wrong Answer)

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Main
{
    public static class Program
    {
        public static List<int> list = new List<int>();

        static void Main(string[] arg)
        {
            var input = GetIntList(Console.ReadLine());
            var answer = 0;

            Console.WriteLine(input[0] + input[1]);




        }
        
        #region libraries
        private static int[] GetIntList(string line)
        {
            return line.Split(' ').Select(x => int.Parse(x)).ToArray();

        }
        private static double[] GetDoubleList(string line)
        {
            return line.Split(' ').Select(x => double.Parse(x)).ToArray();

        }
        private static ulong[] GetUlongList(string line)
        {
            return line.Split(' ').Select(x => ulong.Parse(x)).ToArray();
        }
        private static long[] GetLongList(string line)
        {
            return line.Split(' ').Select(x => long.Parse(x)).ToArray();
        }
        private static int SearchNearest(this IEnumerable<int> list, int target)
        {
            var min = list.Min(c => Math.Abs(c - target));
            return list.First(c => Math.Abs(c - target) == min);
        }
        public static int Gcd(int a,int b)
        {
            if(a < b)
            {
                Gcd(b, a);
            }
            while (b != 0)
            {
                var rm = a % b;
                a = b;
                b = rm;
            }
            return a;
        }
        #endregion
    }
}