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 9.2.1) (judge verdict: Accepted)

#include<cstdio>
int main()
{
	int a,b,n;
	n=0;
	scanf("%d %d",&a,&b);
	if(a>=b){
		n+=a;
		a-=1;
	}
	else{
		n+=b;
		b-=1;
	}
	if(a>=b) n+=a;
	else n+=b;
	printf("%d\n",n);
	return 0;
}