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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include<iostream>
#include<bits/stdc++.h>
#include<string>
#include<vector>
#include<map>
#include<queue>
#include<algorithm>
#include<cmath>
#include<utility>
#include<climits>
#define MAX 1000000
#define pb push_back
#define f first
#define s second

using namespace std;

typedef pair<int, int> pii;
typedef map<int, int> mapint;

int32_t main(){
	int a, b;
	cin>>a>>b;
	int first = max(a, b);
	if (first==a) a = a-1;
	else b = b - 1;
	cout<<first + max(a, b)<<endl;
	return 0;
}