ss="w"> </span><span class="k">then</span>
<span class="k">      do </span><span class="n">ib</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">2</span><span class="p">,</span><span class="w"> </span><span class="n">k</span>
<span class="w">         </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">k</span><span class="o">+</span><span class="mi">1</span><span class="o">-</span><span class="n">i