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<algorithm>//sort(all(変数),greater<型名>())　で降順に
#include<cmath>//切り上げceil(値)
#include<deque>
#include<iomanip>//setprecision(数字)
#include<iostream>
#include<list>
#include<map>
#include<numeric> //xとyの最大公約数は__gcd(x,y),xとyの最小公倍数は(x*y)/__gcd
#include<queue>
#include<set>
#include<stack>
#include<string>
#include<vector>

#include<bits/stdc++.h>
#include<cstdio>
#include<cstdlib>
#include<tuple>
#include<utility>
#define rep(i,n) for(ll i=0; i<n; i++)
#define vll vector<ll>
#define vi vector<int>
#define all(x) (x).begin(),(x).end()
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define mod 1000000007
using ll = long long;
using namespace std;

int main(){
  int a,b;  cin >> a >> b;
  int ans = 0;
  if(b < a){
    ans += a;
    a--;
  }else{
    ans += b;
    b--;
  }

  if(b < a){
    ans += a;
  }else{
    ans += b;
  }
  cout << ans;
  return 0;
}