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.

Examples

Input

5 3


Output

9


Input

3 4


Output

7


Input

6 6


Output

12
import java.util.*;
import java.io.*;

public class Main{
public static void main(String[] args){
Scanner s = new Scanner(System.in);
  int a = s.nextInt();
  int b = s.nextInt();
  int result =0;
  
  if(a>b){
  result = a + Math.max(a-1,b);
  }
  else if(b>a){
    result = b + Math.max(a,b-1);
  }
  else{
  result = 2*a;
  }
  
  System.out.print(result);
  
}
}