import Foundation


while let input_line = readLine() {

    let input_arrs_string = input_line.componentsSeparatedByString(" ")
    
    let n = Int(input_arrs_string[0])!
    let k = Int(input_arrs_string[1])!
    
    if n/2+1 > k {
        print("YES")
    } else {
        print("NO")
    }
    
    
}