> <span class="o">=</span> <span class="mi">0</span>
        <span class="k">while</span> <span class="n">current</span> <span class="o">!=</span> <span
            class="n">first</span><span class="p">:</span>
            <span class="n">euler_tour</span><span class="o">.</span><span class="n">append</span><span
            class="p">(</span><span class="n">current</span><span class="o">.</span><span class="n">data</span><span
            class="p">)</span>
            <span class="n">current</span> <span