Task: Question Answering
Input (English): As shown in Table TABREF3 , we collect Amazon review keywords for 2,896 e-books (publishers: Kiwi, Rowohlt, Fischer, and Droemer), which leads to 33,663 distinct review keywords and on average 30 keyword assignments per e-book. 
 Question: how large is the vocabulary?
Output (English): 33,663