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: Accepted)

def get_coin(a,b,coin=0):
  if a >= b:
    coin += a
    if a > 3:
      a-=1
  else:
    coin += b
    if b > 0:
      b-=1
  return a,b,coin

a = list(map(int,input().split()))
b,c,d = get_coin(a[0],a[1])
e,f,g = get_coin(b,c,d)
print(g)