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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <string>
#include <vector>
#include <math.h>
#include <stdio.h>
#include <algorithm>
#include <cmath>
#define rep0(i,n) for (int i = 0; i <= (n); ++i)
#define rep1(i,n) for (int i = 1; i <= (n); ++i)
using namespace std;
int main(){
	int a, b;
	int ans = 0;
	cin >> a >> b;
	if (a > b)
		ans = a * 2 - 1;
	else if (b > a)
		ans = b * 2 - 1;
	else
		ans = a + b;
	cout << ans << endl;
	return 0;
}