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 Python (3.4.3) (judge verdict: Runtime Error)

#coding:utf-8

if __name__ == "__main__":
    N = int(input())
    tmp = input().split()
    Hs = []
    for t in tmp:
        Hs.append(int(t))
    total = 0

    for n in range(N):
        n_count = 0
        for i in range(0, n):
            if Hs[i] > Hs[n]:
                break
            n_count += 1
        if n_count == n:
            total += 1
        
    print(str(total)+"\n")