title: Should find if the string of numbers is a valid pin
body: <p>For some reason this code prints true for numbers without a length of 4 or 6 and I'm not sure why.</p>
  <pre><code>def validate_pin(pin):
      try:
          pin = int(pin)
      except ValueError:
          print(False)
          exit()
      if len(str(pin)) == 4 or 6:
          if pin &lt; 0:
              print(False)
              exit()
          elif pin &gt;= 0:
              print(True)
              exit()
      elif len(pin) != 4 or 6:
          print(False)
          exit()
  </code></pre>