input: Write a function to check if the given string contains the word "Hello". If it contains the word "Hello" return True else 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("I said hello")==True
  assert check_hello("")==False
  assert check_hello("HELLO")==False
output: def check_hello(s):
      return 'Hello' in s