<div><p>There is a box protected by a password. The password is a sequence of <code>n</code> digits where each digit can be one of the first <code>k</code> digits <code>0, 1, ..., k-1</code>.</p>
<p>While entering a password, the last <code>n</code> digits entered will automatically be matched against the correct password.</p>
<p>For example, assuming the correct password is <code>"345"</code>, if you type <code>"012345"</code>, the box will open because the correct password matches the suffix of the entered password.</p>
<p>Return any password of <strong>minimum length</strong> that is guaranteed to open the box at some point of entering it.</p>
<p> </p>
<p><b>Example 1:</b></p>
<pre><b>Input:</b> n = 1, k = 2
<b>Output:</b> "01"
<b>Note:</b> "10" will be accepted too.
</pre>
<p><b>Example 2:</b></p>
<pre><b>Input:</b> n = 2, k = 2
<b>Output:</b> "00110"
<b>Note:</b> "01100", "10011", "11001" will be accepted too.
</pre>
<p> </p>
<p><b>Note:</b></p>
<ol>
<li><code>n</code> will be in the range <code>[1, 4]</code>.</li>
<li><code>k</code> will be in the range <code>[1, 10]</code>.</li>
<li><code>k^n</code> will be at most <code>4096</code>.</li>
</ol>
<p> </p>
</div>