title: How to find user-defined minimum and maximum value in a list of tuples
body: <p>I have a list of tuples with 2 integers each:</p>
  
  <pre><code>a_list=[(20, 1), (16, 0), (21, 0), (20, 0), (24, 0), (25, 1)]
  </code></pre>
  
  <p>What I am looking for is a way to find and return the tuple that has the smallest second item with the biggest first item. In the above list, it will be the tuple <code>(24, 0)</code>.</p>