title: Length issue in Python3
body: <p>I am taking an Ethical Hacking class, and my lab for the week is trying to crack passwords created by our professor. For this specific challenge, I used a 64 bit decoder to translate his string in his code, and have found the way to solve the problem.</p>
  <p>The issue is when I run the equation found in the code, I run into an error in Python. I'll attach an image for clarification. I do know that length is typically found using len() but I don't know how to use that in this context. The part giving me issues is the [chunk2.length-1].</p>
  <p>I was informed to add the errors I am receiving so here it is:</p>
  <blockquote>
  <p>you = chunk1[2+1]+d[1+1]+h[3]+chunk2[chunk2.length-1] AttributeError: 'str'
  object has no attribute 'length'</p>
  </blockquote>
  <p>Any help provided would be great, thank you guys.</p>