title: How can I get this MARIE program to work for negatives?
body: <p>I wrote this program that will multiply two numbers together but now I need to make it work for negative numbers, anyone have any advice?</p>
  
  <pre><code>org 100
  Input a /first factor
  Store a /store first factor
  Input b /second factor
  Store b /store second factor
  Load a /load first factor
  Skipcond 800 /checks if number is greater than zero
  Jump End /skips to the end if zero
  load b /load second factor
  Skipcond 800 /checks if number is greater than zero
  Jump End /skips to the end if zero
  Loop, Load b /reloads second factor
  Subt One /subtracts one from the second factor
  Store b /store the new value of the second factor
  Load productAB /load the product of the two number; initially zero
  Add a /add first factor to the product
  Store productAB /store new value to product
  Load b/ load second factor again
  Skipcond 400 /end loop if b is equal to 0
  Jump Loop /repeats the loop
  Load productAB /load the value of productAB; no longer 0
  End, output /print out results
  Halt /end of program
  
  a, Dec 0
  b, Dec 0
  productAB, Dec 0 /product of the first two numbers
  One, Dec 1
  </code></pre>