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 (Clang 3.8.0) (judge verdict: Accepted)

#include <iostream>
#include <sstream>
#include <stdio.h>
#include<vector>
#include<climits>
#include<algorithm>
#include<bitset>
#include<cmath>
#include<functional>
#include <numeric>
#include <map>
#define FORi(N) for(int i=0;i<N;++i)
#define FORj(N) for(int j=0;j<N;++j)
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
ll gcd(ll m,ll n){
  if(n==0)return abs(m);
  return(gcd(n,m%n));
}
void putYN(bool b){
  if(b){
    cout<<"YES"<<endl;
  }else{
    cout<<"NO"<<endl;
  }
}
int main(){
  //ll N;
  //cin>>N;
  vector<ll> H(4);
  FORi(2){
    cin>>H[i];
  }
  FORi(2){
    H[i+2]=H[i]-1;
  }
  sort(H.begin(),H.end());
  cout<<H[2]+H[3]<<endl;
  return 0;
}