def main():
  N, K = map(int, input().split())
  if N % 2 == 0:
    X = N / 2
    if X >= K:
      print('YES')
    else:
      print('NO')
  else:
    X = (N + 1)/2
    if X >= K:
      print('YES')
    else:
      print('NO')
main() def main():
  N, K = map(int, input().split())
  if N % 2 == 0:
    X = N / 2
    if X >= K:
      print('YES')
    else:
      print('NO')
  else:
    X = (N + 1)/2
    if X >= K:
      print('YES')
    else:
      print('NO') main N, K = map(int, input().split()) N map(int, input().split()) map int input().split() ().split () input split K if N % 2 == 0:
    X = N / 2
    if X >= K:
      print('YES')
    else:
      print('NO')
  else:
    X = (N + 1)/2
    if X >= K:
      print('YES')
    else:
      print('NO') N % 2 == 0 N % 2 N 2 0 X = N / 2 X N / 2 N 2 if X >= K:
      print('YES')
    else:
      print('NO')
   X >= K X K print('YES') print 'YES' print('NO') print 'NO' X = (N + 1)/2 X (N + 1)/2 N + 1 N 1 2 if X >= K:
      print('YES')
    else:
      print('NO') X >= K X K print('YES') print 'YES' print('NO') print 'NO' main() main def main():
  N, K = map(int, input().split())
  if N % 2 == 0:
    X = N / 2
    if X >= K:
      print('YES')
    else:
      print('NO')
  else:
    X = (N + 1)/2
    if X >= K:
      print('YES')
    else:
      print('NO') def main():
  N, K = map(int, input().split())
  if N % 2 == 0:
    X = N / 2
    if X >= K:
      print('YES')
    else:
      print('NO')
  else:
    X = (N + 1)/2
    if X >= K:
      print('YES')
    else:
      print('NO') main
def main():
  N, K = map(int, input().split())
  if N % 2 == 0:
    X = N / 2
    if X >= K:
      print('YES')
    else:
      print('NO')
  else:
    X = (N + 1)/2
    if X >= K:
      print('YES')
    else:
      print('NO')
main()