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<iostream>
#include<cstring>
//#include<bits/stdc++.h>
#include<math.h>
#include<algorithm>
#include<queue>
#include<stack>
#include<cstdio>
#include<map>
#include<set>
#define  si(a)       scanf("%d",&a)
#define  sl(a)       scanf("%lld",&a)
#define  sii(a,b)    scanf("%d%d",&a,&b)
#define  sll(a,b)    scanf("%lld%lld",&a,&b)
#define  queues      priority_queue
#define mod 1000000007
#define mem(a)  memset(a,0,sizeof(a));
#define def(a) ((a)&(-a))
#define fi  first
#define se  second
#define mp  make_pair
#define  pb push_back
typedef long long ll;
//priority_queue<int,vector<int >,greater<int > >q;
const ll INF=0x3f3f3f3f;
const double E=exp(1);
const double PI=acos(-1);
using namespace std;
ll kc(ll a,ll b)
{
    ll c=1;
    while(b)
    {
        if(b&1)c*=a;
        a*=a;
        b>>=1;
    }return c;
}
ll gcd(ll a,ll b)
{
    return b==0?a:gcd(b,a%b);
}
int s[200003];
bool cmp(int a,int b)
{
    return a>b;
}
int main()
{
  int a,b;
  cin>>a>>b;
  int sum=0;
  if(a>b)
  {
      sum=a+max(b,a-1);
  }
  else sum+=b+max(a,b-1);
  cout<<sum<<endl;
}
/******************************************
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**       ** **           **             **
**      **   **          **             **
**     **     **         **             **
**    ***********        **             **
**   **         **       ********       **
******************************************/