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 <stdio.h>
#include <math.h>

void sort(int *arr, int n);

int main(){
    int a,b;
    scanf("%d %d\n", &a, &b);
    int m1,m2,m3,ans;
    m1 = a + (a-1);
    m2 = b + (b-1);
    m3 = a + b;
    int arr[4];
    arr[0] = m1;
    arr[1] = m2;
    arr[2] = m3;

    sort(arr, 3);

    ans = arr[2];

    printf("%d\n", ans);

}

void sort(int *arr, int n){
    int i,j,temp=0;
    for(i=0;i<n-1;i++){
        for(j=0;j<n-1;j++){
            if(arr[j] > arr[j+1]){
                temp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = temp;
            }
        }
    }
}