span> <span class="mi">1</span><span class="p">,</span> <span class="nb">len</span><span class="p">(</span><span class="n">sequence</span><span class="p">)</span> <span class="o">+</span> <span class="mi">1</span><span class="p">):</span>
            <span class="k">if</span> <span class="n">left</span> <span class="o">==</span> <span class="mi">0</span> <span class="ow">and</span> <span class="n">right</span> <span class="o">==</span> <span class="nb">len</span><span class="p">(</span><span class="n">seque