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 Go (1.6) (judge verdict: Wrong Answer)

package main

import (
  "fmt"
  "bufio"
  "os"
)

func main() {
  count := [2] int{0, 0}

  sc := bufio.NewScanner(os.Stdin)
  buf := make([]byte, 100000)
  sc.Buffer(buf, 100000)
  sc.Scan()
  s := sc.Text()

  n := len(s)

  for i := 0; i < n; i++ {
    if i % 2 == 0 {
      if s[i] == 48 {
        count[0]++
      } else {
        count[1]++
      }
    } else {
      if s[i] == 48 {
        count[1]++
      } else {
        count[0]++
      }
    }
  }

  if count[0] < count[1] {
    fmt.Println(count[0])
  } else {
    fmt.Println(count[1])
  }
}