span class="p">[</span><span class="n">h</span><span class="o">-</span><span class="mi">1</span><span class="p">])[</span><span class="mi">1</span><span class="p">]</span>
    <span class="n">l0</span><span class="p">,</span> <span class="n">l1</span> <span class="o">=</span> <span class="nb">len</span><span class="p">(</span><span class="n">z0</span><span class="p">),</span> <span class="nb">len</span><span class="p">(</span><span class="n">z1</span><span class="p">)</span>

    <span class="k">if</span> <