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: Runtime Error)

/*coderanant*/
#include <bits/stdc++.h>
using namespace std;

#define int long long
#define ll long long
#define f1(i,a,b) for(i=a;i<b;i++)
#define f2(i,a,b) for(i=a;i>=b;i--)
#define endl '\n'
#define pb push_back
#define gp " "
#define ff first
#define ss second
#define mp make_pair

const int mod=1000000007;
int i,j;
ll temp;

int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    #ifndef ONLINE_JUDGE
    	freopen("in.txt","r",stdin);
    	freopen("out.txt","w",stdout);
    #endif
    int a,b;
    cin>>a>>b;
    int ans=a+b;
    if(2*a-1>ans)
    	ans=2*a-1;
    if(2*b-1>ans)
    	ans=2*b-1;
    cout<<ans;
    return 0;
}