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 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <string.h>
 
int main(){
  int i,flag=0,acount=0,bcount=0;
  char s[100001];
  scanf("%s",s);
    for(i=0;i<strlen(s);i++){
      if(flag == 0){
        if(s[i]=='0') acount++;
        else bcount++;
        flag=1;
      }
      else{
        if(s[i]=='1') acount++;
        else bcount++;
        flag=0;
      }
    }
 
    if(acount>bcount) printf("%d",strlen(s)-acount);
    else printf("%d",strlen(s)-bcount);
  return 0;
}