n, k = map(int, raw_input().split())
n = (n + 1)/2
if k <= n:
  print "YES"
else:
  print "NO" n, k = map(int, raw_input().split()) n map(int, raw_input().split()) map int raw_input().split() ().split () raw_input split k n = (n + 1)/2 n (n + 1)/2 n + 1 n 1 2 if k <= n:
  print "YES"
else:
  print "NO" k <= n k n print print n, k = map(int, raw_input().split()) map(int, raw_input().split()) n k = map(int, raw_input().split()) map(int, raw_input().split()) k n = (n + 1)/2 (n + 1)/2 n
n, k = map(int, raw_input().split())
n = (n + 1)/2
if k <= n:
  print "YES"
else:
  print "NO"