input: Write a function to multiply two given input numbers and print the result.
  assert multiply(3, 4) == None
  assert multiply(5, 2) == None
  assert multiply(0, 0) == None
  assert multiply(-1, 1) == None
  assert multiply(3.5, 2) == None
output: def multiply(a, b):
      result = a * b
      print(result)