Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

Example Input: the wwe united states championship is a professional wrestling championship in world wrestling entertainment (wwe).
Example Output: wwe united states championship

Example Input: child development refers to biological, psychological and emotional changes that happen in humans between birth and the end of adolescence, at which time the individual goes from dependence to independence.
Example Output: child development

Example Input: carey bell (*14 november 1936 in macon, mississippi - † 6 may 2007 in chicago, illinois) was an american blues musician.
Example Output:
carey bell