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)

// スタックサイズ: 100MB

#include <iostream>
#include <fstream>
#include <vector>
#include <map>
#include <unordered_map>
#include <string>
#include <cmath>
#include <cstdio>
#include <algorithm>
#include <functional>
#include <numeric>
#include <iomanip>
#include <queue>
#include <list>
#include <set>
using namespace std;

typedef long long ll;
typedef vector<ll> vll;
typedef pair<ll, ll> pll;
const ll INF = 1000000000000000000;
#define fori(i, a, b) for (ll i = (a); i < (b); ++i)
#define ford(i, a, b) for (ll i = (b - 1); (a) <= i; --i)
#define rep(i, n) fori(i, 0, n)
#define all(v) (v).begin(), (v).end()
ll pw(ll x, ll y) { ll r = 1;  rep(i, y) { r *= x; }; return r; }


int main() {
	
	ll a, b;
	cin >> a >> b;
	if (a != b)cout << 2 * max(a, b) - 1 << endl;
	else cout << 2 * a << endl;
}