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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)


import java.io.*;
import java.util.Scanner;
import java.util.TreeSet;

public class Main{
    /*public static void */
    public static void main(String []args) throws IOException
    {
        Scanner sc = new Scanner (System.in);

        int n = sc.nextInt();
        int k = sc.nextInt();

        if(n%k==1)
            System.out.println("YES");
        else
            System.out.println("NO");
    }
}