Problem:
Score : 100 points

Problem Statement

Determine if we can choose K different integers between 1 and N (inclusive) so that no two of them differ by 1.

Constraints

1\leq N,K\leq 100

N and K are integers.

Input

Input is given from Standard Input in the following format:

N K

Output

If we can choose K integers as above, print YES; otherwise, print NO.

Sample Input 1

3 2

Sample Output 1

YES

We can choose 1 and 3.

Sample Input 2

5 5

Sample Output 2

NO

Sample Input 3

31 10

Sample Output 3

YES

Sample Input 4

10 90

Sample Output 4

NO

Solution in Julia (0.5.0) (judge verdict: Wrong Answer)

function main()
  
  (N,K) = map(x -> parse(Int,x), split(readline()))
  
  count = 0
  
  for i in N:-1:2
    
    count += (N-2)
    
  end
  
  if count > K
    println("YES")
  else
    println("NO")
  end
  
end

main()