Which is a complex sentence?

 - Madison Chock and Gracie Gold were two American figure skaters in the Sochi 2014 Olympics.
 - If you are sleepy, you should go to bed early tonight.
The second sentence is the complex sentence. It is made up of an independent clause and a dependent clause. The dependent clause begins with the subordinating conjunction if.
If you are sleepy, you should go to bed early tonight.