input: Write a function to return True if the given string contains the word "Hello", otherwise return False.
  def check_hello(s):
      return 'Hello' in s
  assert check_hello("Hello World")==True
  assert check_hello("Hi there")==False
  assert check_hello("Welcome Hello")==True
  assert check_hello("Hello")==True
  assert check_hello("Goodbye")==False
output: def check_hello(s):
      return 'Hello' in s