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: Accepted)

package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strconv"
)

var sc *bufio.Scanner

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func answer(reader io.Reader, writer io.Writer) {
	sc = bufio.NewScanner(reader)
	sc.Split(bufio.ScanWords)
	a := nextInt()
	b := nextInt()
	var c int
	if a > b {
		c = a
		a--
	} else {
		c = b
		b--
	}
	if a > b {
		c += a
		a--
	} else {
		c += b
		b--
	}
	_, _ = fmt.Fprintf(writer, "%d", c)
}

func main() {
	answer(os.Stdin, os.Stdout)
}