an class="n">append</span><span class="p">(</span><span class="n">i</span><span class="p">)</span>
        <span class="n">items</span> <span class="o">=</span> <span class="nb">list</span><span class="p">(</span><span class="nb">set</span><span class="p">(</span><span class="nb">map</span><span class="p">(</span><span class="nb">tuple</span><span class="p">,</span> <span class="n">items</span><span class="p">)))</span>
        <span class="k">return</span> <span class="nb">len</span><span class="p">(</span