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 <stdlib.h>
#include <string.h>
#include <memory.h>
#include <limits.h>
#include <math.h>

int main(int argc, char *argv[])
{
    int a, b;
    int i;
    int ans;

    scanf("%d %d", &a, &b);

    ans = 0;
    for (i = 0; i < 2; i++) {
        if (a < b) {
            ans += b;
            b--;
        } else {
            ans += a;
            a--;
        }
    }

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

    return 0;
}