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 JavaScript (node.js v5.12) (judge verdict: Runtime Error)

function main(arg) {
    const [_n, _k] = arg.replace(/\r?\n/g,"").split(" ")
    const n = Number(_n)
    const k = Number(_k)

    if(n + 1 - (k * 2) >= 0){
        console.log("YES")
    }else{
        console.log("NO")
    }
}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));