input: Write a function to check if a given string contains the word "Hello". If it does, return True, otherwise return False. If the given string is empty, return False.
  assert check_hello("Hello World!")==True
  assert check_hello("Hi there.")==False
  assert check_hello("This is a hello message.")==True
  assert check_hello("")==False
  assert check_hello("HELLO")==False
  assert check_hello("Hello123")==True
output: def check_hello(s):
      return "Hello" in s if s else False