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,c=0;
  scanf("%d%d",&a,&b);
 //2a-1 2b-1 a+b
  if(a>=b)
  {
    if(2*a-1>=a+b)
    {
      c=2*a-1;
    }else
    {
      c=a+b;
    }
  }  
  else
  {
    c=2*b-1;
  }
  printf("%d",c);
  return 0;
}