instruction: return me the number of papers written by ' H. V. Jagadish ' and ' Divesh Srivastava ' .
response: SELECT COUNT(DISTINCT (publication.title)) FROM author AS AUTHOR_0, author AS AUTHOR_1, publication, writes AS WRITES_0, writes AS WRITES_1 WHERE AUTHOR_0.name = 'H. V. Jagadish' AND AUTHOR_1.name = 'Divesh Srivastava' AND WRITES_0.aid = AUTHOR_0.aid AND WRITES_0.pid = publication.pid AND WRITES_1.aid = AUTHOR_1.aid AND WRITES_1.pid = publication.pid