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