###template###
import sys
input = sys.stdin.readline
def mi(): return map(int, input().split())
###template###

N, K = mi()

if N >= (K*2 - 1):
  print('YES')
else: print('NO')
 import sys sys input = sys.stdin.readline input sys.stdin.readline sys.stdin sys stdin readline def mi(): return map(int, input().split())
###template### mi N, K = mi() N mi() mi K if N >= (K*2 - 1):
  print('YES')
else: print('NO') N >= (K*2 - 1) N K*2 - 1 K*2 K 2 1 print('YES') print 'YES' input = sys.stdin.readline sys.stdin.readline input K = mi() mi() K def mi(): return map(int, input().split())
###template### def mi(): return map(int, input().split())
###template### mi N, K = mi() mi() N
###template###
import sys
input = sys.stdin.readline
def mi(): return map(int, input().split())
###template###

N, K = mi()

if N >= (K*2 - 1):
  print('YES')
else: print('NO')

