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 (GCC 5.4.1) (judge verdict: Runtime Error)

#include <unistd.h>

void	js_printnbr(int nbr)
{
	char	c;

	if (10 < nbr)
	{
		js_printnbr(nbr / 10);
		js_printnbr(nbr % 10);
	}
	else
	{
		c = nbr + '0';
		write(1, &c, 1);
	}
}

int		js_atoi(char *str)
{
	int		result;
	int		i;

	result = 0;
	i = 0;
	while ('0' <= str[i] && str[i] <= '9')
	{
		result = result * 10 + (str[i] - '0');
		i++;
	}
	return (result);
}

int		main(int argc, char **argv)
{
	(void)argc;
	int		i;
	int		num[2];
	int		result;

	i = -1;
	result = 0;
	while (++i < 2)
		num[i] = js_atoi(argv[i + 1]);
	i = 0;
	while (i < 2)
	{
		if (num[0] > num[1])
		{
			result = result + num[0];
			num[0]--;
		}
		else
		{
			result = result + num[1];
			num[1]--;
		}
		i++;
	}
	js_printnbr(result);
}