title: Write a function that adds lists elements using *args
body: <p>I would like to write a function that calculates scalar sum of several vectors. It should take several lists as arguments eg.</p>
  
  <pre><code>def add_lists(x, y, z):
     # return sum of x, y, z
  
  x = add_lists([1, 2],[2, 1],[3, 1])
  # x returns [6, 4]
  </code></pre>
  
  <p>It is easy to do it for only two arguments, but how can I do it using *args if they are more than two, so that my <code>add_lists</code> will return [6, 4]? </p>