title: Find duplicate element in a list of lists
body: <p>I am looking for Python ideas for the following problem.</p>
  
  <p>Given a list of lists...</p>
  
  <pre><code>[[20, 21, 22], [17, 18, 19, 20], [10, 11, 12, 13]]
  </code></pre>
  
  <p>If there is a duplicate element that is common between any or all the lists, return True. If all of the elements are unique, return False.</p>
  
  <p>In the example above, 20 is common and would return True. The example below would return False because all the numbers are unique between the lists.</p>
  
  <pre><code>[[20, 21, 22], [17, 18, 19], [10, 11, 12, 13]]
  </code></pre>
  
  <p>Lastly, testing for duplicates in an individual list is not needed because the numbers are always sequential.</p>
  
  <p>FYI - this problem will be used to optimize an airline crew members monthly schedule. Each list represents a 3, 4, or 5 day airline trips that can't overlap.</p>
  
  <p>BTW - this problem is not an assignment but a personal quest to work less and get paid more :) Sorry it was unclear. I tried a brute force method which works but was hoping for a more elegant Pythonic method. I appreciate all the responses as they are leading me into new areas of Python programming.</p>