pan><code><span id="__span-3-1"><a href="#__codelineno-3-1" id="__codelineno-3-1" name="__codelineno-3-1"></a><span class="p">(</span><span class="k">define</span><span class="w"> </span><span class="nv">drones</span>
</span><span id="__span-3-2"><a href="#__codelineno-3-2" id="__codelineno-3-2" name="__codelineno-3-2"></a><span class="w">  </span><span class="p">(</span><span class="k">lambda</span><span class="w"> </span><span class="p">(</span><span class="nf">beat</span><span class="p">)</span>
</span><