title: Finding intersected elements of lists in a dictionary
body: <p>I'm working with Python 3 and I have a dictionary: </p>
  
  <pre><code>{'investment': [2,62,634,654], 
  'companies': [2, 30, 62, 53, 66, 279, 281],
  'products': [2, 30, 49,128,562,62]
   .
   .
   .
  }
  </code></pre>
  
  <p>I don't know the size of dictionary. (It changes according to the input taken from the customer.)</p>
  
  <p>The question is how can I fetch the interceptions of elements of the dictionary as an output? 
  For the sample the final output should be <code>[2,62]</code></p>