number_list = [int(i) for i in input().split()]

if number_list[0] % 2 == 0:#偶数のとき
  if number_list[0] >= number_list[1]*2:
    print('YES')
  else:
    print('NO')
else:
  if number_list[0] + 1 >= number_list[1]*2:
    print('YES')
  else:
    print('NO') int(i) for i in input().split() for i in input().split() i input().split() ().split () input split for i in input().split() int(i) int i number_list = [int(i) for i in input().split()] number_list [int(i) for i in input().split()] if number_list[0] % 2 == 0:#偶数のとき
  if number_list[0] >= number_list[1]*2:
    print('YES')
  else:
    print('NO')
else:
  if number_list[0] + 1 >= number_list[1]*2:
    print('YES')
  else:
    print('NO') number_list[0] % 2 == 0 number_list[0] % 2 number_list[0] number_list 0 2 0 if number_list[0] >= number_list[1]*2:
    print('YES')
  else:
    print('NO') number_list[0] >= number_list[1]*2 number_list[0] number_list 0 number_list[1]*2 number_list[1] number_list 1 2 print('YES') print 'YES' print('NO') print 'NO' if number_list[0] + 1 >= number_list[1]*2:
    print('YES')
  else:
    print('NO') number_list[0] + 1 >= number_list[1]*2 number_list[0] + 1 number_list[0] number_list 0 1 number_list[1]*2 number_list[1] number_list 1 2 print('YES') print 'YES' print('NO') print 'NO' number_list = [int(i) for i in input().split()] [int(i) for i in input().split()] number_list
number_list = [int(i) for i in input().split()]

if number_list[0] % 2 == 0:#偶数のとき
  if number_list[0] >= number_list[1]*2:
    print('YES')
  else:
    print('NO')
else:
  if number_list[0] + 1 >= number_list[1]*2:
    print('YES')
  else:
    print('NO')