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 max(int x,int y);
int main()
{
	int a,b;
	scanf("%d %d",&a,&b);
	printf("%d",max(a,b));
}
int max(int x,int y)
{
	if(2*x-1>x+y){
		if(2*x-1>2*y-1){
			return(2*x-1);
		}else{
			return(2*y-1);
		}
	}else{
		if(x+y>2*y-1){
			return(x+y);
		}else{
			return(2*y-1);
		}
	}
}