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: Accepted)

#include<stdio.h>
int main(void)
{
	int a, b;
	int c, d, e;

	scanf("%d %d", &a, &b);

	c = 2 * a - 1;
	d = a + b;
	e = 2 * b - 1;

	if (c <= d && d <= e || d <= c && c <= e)
		printf("%d", e);
	else {
		if (c <= e && e <= d || e <= c && c <= d)
			printf("%d", d);
		else {
			if (d <= e && e <=c || e <= d && d <= c)
				printf("%d", c);
		}
	}
	return 0;
}