an class="ne">ValueError</span><span class="p">(</span><span class="s1">&#39;&quot;a&quot; must have two elements&#39;</span><span class="p">)</span>
            <span class="k">else</span><span class="p">:</span>
                <span class="n">y</span> <span class="o">=</span> <span class="n">a</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span>
        <span class="k">else</span><span class="p">:</span>
            <span class="n">x</span> <span class="o">=</span> <span class=