Answer the following question: Given the following passage  "Artists contributing to this format include mainly soft rock/pop singers such as, Andy Williams, Johnny Mathis, Nana Mouskouri, Celine Dion, Julio Iglesias, Frank Sinatra, Barry Manilow, Engelbert Humperdinck, and Marc Anthony.",  answer the following question. Note that the answer is present within the text.  Question: What is Engelbert Humperdinck's last name?
Answer:
Humperdinck