title: Finding index of number from another list
body: <p>I am using Python 3, and I have two lists in my code:</p>
  
  <pre><code>ListA = [53, 1, 17, 4, 13, 2, 17]
  ListB = [4, 3, 1]
  </code></pre>
  
  <p>Now, I want to find the index of any number in ListB that is in ListA.</p>
  
  <p>The output in this case should be <code>1</code> because:</p>
  
  <ul>
  <li>The first value in <code>ListA</code> which is also in <code>ListB</code> is <code>1</code>.</li>
  <li>The index of value <code>1</code> in <code>ListA</code> is <code>1</code>.</li>
  </ul>