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: Wrong Answer)

#include<iostream>
#include<cstring>
#include<string>
#include<cmath>
#include<vector>
#include<algorithm>
#include<iterator>
#include<sstream>
#include<iomanip>
#include<map>

#define rep(i, n) for (int i = 0; i < n; i++) 
#define rrep(i, n) for(int i = n-1; i>=0; i--)
#define range(i, n, m) for (int i = n; i < m; i++) 
#define rrange(i, n, m) for (int i = n - 1; i => m; i--) 
#define MOD 1000000007
#define MAX 20000000000

typedef long long int ll;
typedef unsigned long long int ull;


using namespace std;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }


int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);

	ll A, B;
	cin >> A >> B;

	ll ret = 0;

	if (A == B) {
		ret = A * 2;
	}
	else {
		ll m = max(A, B);
		ret = A + (A - 1);
	}

	cout << ret << endl;

	
	return 0;
}