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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>

int main(void)
{
  int n, m, i, cnt = 0;
  
  scanf("%d %d", &n, &m);
  
  for(i = 1;i <= n;i++)
  {
    if(i != n-1)
    {
      cnt++;
    }
  }
  
  if(cnt >= m)
  {
    printf("YES\n");
  }
  else
  {
    printf("NO\n");
  }
}