input: Write a function to determine if the given string contains the word "Hello". If it does, return True; otherwise, return False.
  assert check_hello("Hello, World!") == True
  assert check_hello("Hi there!") == False
  assert check_hello("Say Hello to everyone.") == True
  assert check_hello("") == False
  assert check_hello("hello") == False
output: def check_hello(s):
      return "Hello" in s