input: Write a function to check if a given string contains the word "Hello". If it does, return True; 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("Say Hello to everyone")==True
  assert check_hello("This is a test")==False
  assert check_hello("Hello")==True
output: def check_hello(s):
      return 'Hello' in s