title: Make an array work like a circle
body: <p>I'm not quite sure how to do this.</p>
  
  <p>pseudocode:</p>
  
  <pre><code>array1 = {"a","b", "c", "d", "e","f", "g","h", "i","j"} //there might be more values.
  take c
  loop =&gt;c+3 =f
         f+3 =i
         i+3 =b
         b+3 =e
  ......
  end loop
  </code></pre>
  
  <p>I need to work this <code>array1</code> as a <strong>circle</strong> and find the letters adding 3 (f, i, b, e, and more).</p>