evious use in the perfect number warmup.  Open the file <code class="language-c++ highlighter-rouge"><span class="n">main</span><span class="p">.</span><span class="n">cpp</span></code> and edit the <code class="language-c++ highlighter-rouge"><span class="n">main</span><span class="p">()</span></code> to comment out the call to <code class="language-c++ highlighter-rouge"><span class="n">findPerfects</span></code> and uncomment the call to <code class="language-c++ highlighter-rouge"><span class="n">sounde