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>
#include <ctype.h>

void print_int(int n)
{
    printf("%d\n",n);
}

void swap(int * a, int * b)
{
    int t = *a;
    *a = *b;
    *b = t;
}

void sort(int a[], int n)
{
    for(int i = 1; i < n; i++)
    {
        int j = i-1;
        while(j >= 0 && a[j+1] > a[j])
        {
            swap(&a[j+1],&a[j]);
            j--;
        }
        
    }
    
}

int main(int argc, char * argv[])
{
    int button[2];
    int coin[3];
    scanf("%d %d",&button[0], &button[1]);

    coin[0] = button[0] + button[1];
    coin[1] = button[0] + button[0] - 1;
    coin[2] = button[1] + button[1] - 1;

    sort(coin, 3);

    print_int(coin[0]);
    return 0;
}