import sys
# import math
# import decimal
# import queue
# import bisect
# import heapq
import time
# import itertools

mod = int(1e9+7)
INF = 1<<29

def main():
    n,k = map(int,input().split())
    if (n + 1) // 2 >= k:
        print("YES")
    else:
        print("NO")
    return

if __name__=='__main__':
    main() import sys sys import time time mod = int(1e9+7) mod int(1e9+7) int 1e9+7 1e9 7 INF = 1<<29 INF 1<<29 1 29 def main():
    n,k = map(int,input().split())
    if (n + 1) // 2 >= k:
        print("YES")
    else:
        print("NO")
    return main n,k = map(int,input().split()) n map(int,input().split()) map int input().split() ().split () input split k if (n + 1) // 2 >= k:
        print("YES")
    else:
        print("NO")
     (n + 1) // 2 >= k (n + 1) // 2 n + 1 n 1 2 k print("YES") print "YES" print("NO") print "NO" return if __name__=='__main__':
    main() __name__=='__main__' __name__ '__main__' main() main INF = 1<<29 1<<29 INF mod = int(1e9+7) int(1e9+7) mod def main():
    n,k = map(int,input().split())
    if (n + 1) // 2 >= k:
        print("YES")
    else:
        print("NO")
    return def main():
    n,k = map(int,input().split())
    if (n + 1) // 2 >= k:
        print("YES")
    else:
        print("NO")
    return main
import sys
# import math
# import decimal
# import queue
# import bisect
# import heapq
import time
# import itertools

mod = int(1e9+7)
INF = 1<<29

def main():
    n,k = map(int,input().split())
    if (n + 1) // 2 >= k:
        print("YES")
    else:
        print("NO")
    return

if __name__=='__main__':
    main()