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 <sstream>
#include <vector>
#include <cmath>
#include <ctime>
#include <cassert>
#include <iomanip>
#include <vector>
#include <cstdio>
#include <float.h>
#include <queue>
#include <set>
#include <map>
#include <fstream>
#include <cstdlib>
#include <string>
#include <cstring>
#include <algorithm>
#include <numeric>
#include <stack>
#include <functional>
 
using namespace std;
 
#define endl '\n'
#define MOD 1000000007
#define INF 1ll<<30
#define MAX 100010
#define eps 1e-11
#define bit_max 1ll<<32
#define _USE_MATH_DEFINES

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    
    int a,b;
    cin>>a>>b;
    cout<<max(a+b,max(a+a-1,b+b-1));
    return 0;
}