Which is a compound sentence?

 - He showed the officers a hotel receipt and an airplane ticket as proof of his time in Buenos Aires.
 - Lucy accidentally spilled her glass of juice, but luckily it didn't get on the white sofa.
The first sentence is the compound sentence. It is made up of two independent clauses joined by the coordinating conjunction but.
Lucy accidentally spilled her glass of juice, but luckily it didn't get on the white sofa.