# -*- coding: utf-8 -*-
 
import math
import itertools
import sys
import copy
 
# 入力
#A, B, C, D = map(int, input().split())
#L = list(map(int, input().split()))
#S = list(str(input()))
#N = int(input())
N, K = map(int, input().split())

if N%2 == 0 :
  if N//2 >= K :
    print ("YES")
  else :
    print ("NO")
else :
  if N//2 + 1 >= K :
    print ("YES")
  else :
    print ("NO")
   import math math import itertools itertools import sys sys import copy copy N, K = map(int, input().split()) N map(int, input().split()) map int input().split() ().split () input split K if N%2 == 0 :
  if N//2 >= K :
    print ("YES")
  else :
    print ("NO")
else :
  if N//2 + 1 >= K :
    print ("YES")
  else :
    print ("NO")
   N%2 == 0 N%2 N 2 0 if N//2 >= K :
    print ("YES")
  else :
    print ("NO") N//2 >= K N//2 N 2 K print ("YES") print "YES" print ("NO") print "NO" if N//2 + 1 >= K :
    print ("YES")
  else :
    print ("NO")
   N//2 + 1 >= K N//2 + 1 N//2 N 2 1 K print ("YES") print "YES" print ("NO") print "NO" N, K = map(int, input().split()) map(int, input().split()) N K = map(int, input().split()) map(int, input().split()) K
# -*- coding: utf-8 -*-
 
import math
import itertools
import sys
import copy
 
# 入力
#A, B, C, D = map(int, input().split())
#L = list(map(int, input().split()))
#S = list(str(input()))
#N = int(input())
N, K = map(int, input().split())

if N%2 == 0 :
  if N//2 >= K :
    print ("YES")
  else :
    print ("NO")
else :
  if N//2 + 1 >= K :
    print ("YES")
  else :
    print ("NO")
  
