 class="computeroutput"><span class="identifier">X</span><span class="special">&amp;</span></code>
                  </p>
                </td>
<td>
                  <p>
                    <code class="computeroutput"><span class="keyword">return</span> <span class="identifier">r</span>
                    <span class="special">+=</span> <span class="special">-</span><span class="identifier">n</span></code>
                  </p>
                </td>
<td>
                </td>
</tr>
<tr>
<td>
           