SELECT COUNT ( DISTINCT t7.title ) FROM writes AS t4 JOIN author AS t2 ON t4.aid  =  t2.aid JOIN publication AS t7 ON t4.pid  =  t7.pid JOIN writes AS t5 ON t5.pid  =  t7.pid JOIN writes AS t6 ON t6.pid  =  t7.pid JOIN author AS t1 ON t5.aid  =  t1.aid JOIN author AS t3 ON t6.aid  =  t3.aid WHERE t2.name  =  "Cong Yu" AND t1.name  =  "H. V. Jagadish" AND t3.name  =  "Yunyao Li";
return me the number of papers written by " H. V. Jagadish " , " Yunyao Li " , and " Cong Yu " .
[Schema (values) (types)]: | academic |  author : aid (text) , homepage (number) , name (text) , oid (text) | conference : cid (text) , homepage (number) , name (text) | domain : did (text) , name (number) | domain_author : aid (text) , did (number) | domain_conference : cid (text) , did (number) | journal : homepage (text) , jid (number) , name (text) | domain_journal : did (text) , jid (number) | keyword : keyword (text) , kid (number) | domain_keyword : did (text) , kid (number) | publication : abstract (text) , cid (number) , citation_num (text) , jid (text) , pid (number) , reference_num (number) , title (text) , year (text) | domain_publication : did (text) , pid (number) | organization : continent (text) , homepage (number) , name (text) , oid (text) | publication_keyword : pid (text) , kid (number) | writes : aid (text) , pid (number) | cite : cited (text) , citing (number);