n> <span class="s1">&#39;@&#39;</span> <span class="k">then</span> <span class="nx">i</span> <span class="o">-</span> <span class="mi">2</span> <span class="k">else</span> <span class="nx">i</span> <span class="o">-</span> <span class="mi">1</span>
      <span class="nx">idx</span> <span class="o">-=</span> <span class="mi">2</span> <span class="k">while</span> <span class="nx">@tag</span><span class="p">(</span><span class="nx">idx</span> <span class="o">-</span> <span class="mi">2</span><span class="p">)<