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: Runtime Error)

#include<stdio.h>
void main(void){
	int A;
	int B;
	int i;
	int sum = 0;
 
	scanf("%d", &A);
	scanf("%d", &B);
 
	for (i = 0; i < 2; i++){
      if(A >= B){
        sum += A;
        A--;
      }
      else{
        sum += B;
        B--;
      }
    }
 
	printf("%d\n", sum);
}