input: Write a function to create a Python program that multiplies two input numbers and prints the result. The function should take two arguments, multiply them, and print the result. If either of the input numbers is zero, the function should print 0.
  assert multiply(3, 4)==None
  assert multiply(0, 4)==None
  assert multiply(3, 0)==None
  assert multiply(-3, 4)==None
  assert multiply(-3, -4)==None
output: def multiply(a, b):
      if a == 0 or b == 0:
          print(0)
      else:
          print(a * b)