title: How to assign auto-increment values to a combination of (k,v) pairs of a dict in Python3?
body: <p>I have a dictionary in the following format. I have made sure the keys are in sorted order, and also so are the values for those keys</p>
  <pre><code>{67: ['226', '2470', '2517', '2578', '2799', '281', '2905', '3015', '3081', '347', '411'], 68: ['276', '331', '387', '442', '497', '607', '662']}
  </code></pre>
  <p>Now, I want to assign an auto-incrementing integer to each combination of a k,v pair.</p>
  <p>Example:</p>
  <pre><code>{(67, 226):1, (67, 2470): 2 ...  (68, 662):18}
  </code></pre>