<p>We define the string <code>base</code> to be the infinite wraparound string of <code>"abcdefghijklmnopqrstuvwxyz"</code>, so <code>base</code> will look like this:</p>
<p>Given a string <code>s</code>, return <em>the number of <strong>unique non-empty substrings</strong> of </em><code>s</code><em> are present in </em><code>base</code>.</p>
<strong>Explanation:</strong> There are six substrings ("z", "a", "b", "za", "ab", and "zab") of s in base.