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;
using System.Text;
using System.Threading.Tasks;

namespace ABC124 {
	class ABC124_A {
		static void Main(string[] args) {
			// ABの入力を受け付け、intでパースする
			// 合計を保存するための変数を用意する
			// ABの数字を比較して、大きい方の値を合計の変数に加算する
			// その処理を2回繰り返す

			var AB = Console.ReadLine().Split(' ').Select(s => int.Parse(s)).ToArray();
			var A = AB[0];
			var B = AB[1];

			var total = 0;
			for (int i = 0; i < 2; i++) {
				if (A > B) {
					total += A--;
				} else {
					total += B--;
				}
			}

			Console.WriteLine(total.ToString());
		}
	}
}