input: Write a function to multiply two input numbers and print the result.
  def multiply(a, b):
      result = a * b
      print(result)
  
  assert multiply(3, 4)==12
  assert multiply(5, 6)==30
  assert multiply(7, 8)==56
  assert multiply(2, 0)==0
  assert multiply(-1, 1)==-1
output: def multiply(a, b):
      result = a * b
      print(result)