input: Write a function to determine if a given string contains the word "Hello". If it contains "Hello" return True, otherwise return False. If the given string is empty then return False.
  def check_hello(s):
      if s == "":
          return False
      return 'Hello' in s
  assert check_hello("Hello world")==True
  assert check_hello("Hi there")==False
  assert check_hello("")==False
output: def check_hello(s):
      if s == "":
          return False
      return 'Hello' in s