,</span> <span class="n">site_i</span> <span class="o">=</span> <span class="n">queue</span><span class="o">.</span><span class="n">pop</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>

        <span class="k">if</span> <span class="n">comp_i</span> <span class="ow">in</span> <span class="p">[</span><span class="n">x</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <sp