input: Write a function to determine if the given string contains the word "Hello". If the word "Hello" is found in the string, the function should return True; otherwise, it should 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("This is a test")==False
  assert check_hello("")==False
output: def check_hello(s):
      return "Hello" in s