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 (Clang 3.8.0) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <stdlib.h>
int main(void){
    
    int x,y;
    char line[100];
    fgets(line,sizeof(line),stdin);
    sscanf(line,"%d",&x);
    fgets(line,sizeof(line),stdin);
    sscanf(line,"%d",&y);
    
  	if( x-y  == 0){
    	printf("%d",x+y);  
    }else{
      if(x>=y){
        printf("%d",(x<<1)-1);
      }else{
        printf("%d",(y<<1)-1);
      }
    }
    
    
    return 0;
}