1 main<span class="br0">(</span>n<span class="br0">)</span><span class="br0">{</span><span class="kw1">return</span> n<span class="sy0"><</span>2<span class="sy0">?:</span>main<span class="br0">(</span>n<span class="sy0">-</span>1<span class="br0">)</span><span class="sy0">+</span>main<span class="br0">(</span>n<span class="sy0">-</span>2<span class="br0">)</span><span class="sy0">;</span><span class="br0">}</span>