       <span class="n">rank1</span> <span class="o">=</span> <span class="n">rank</span><span class="p">(</span><span class="n">seen</span><span class="o">.</span><span class="n">union</span><span class="p">({</span><span class="n">candidate</span><span class="p">}))</span>
        <span class="k">return</span> <span class="n">rank1</span> <span class="o">&gt;</span> <span class="n">rank0</span>

    <span class="n">connected_sites</span> <span class="o">=</span> <span class="p">{</span><span class="n">i</s