-- Database schema
| cites : cited_paper_id [ TEXT ] , citing_paper_id [ TEXT ] | paper : paper_id [ TEXT ] primary_key , class_label [ TEXT ] | content : paper_id [ TEXT ] content.paper_id = paper.paper_id , word_cited_id [ TEXT ] |
-- -- Which paper ID cited the most word? In which class label does it belongs to?

SELECT T1.paper_id, T1.class_label FROM paper AS T1 INNER JOIN content AS T2 ON T1.paper_id = T2.paper_id GROUP BY T1.paper_id, T1.class_label ORDER BY COUNT(T2.word_cited_id) DESC LIMIT 1;