Database: academic
Question: return me the number of authors who have cooperated with " H. V. Jagadish " .
SQL: select count ( distinct t2.name ) from writes as t3 join author as t2 on t3.aid  =  t2.aid join publication as t5 on t3.pid  =  t5.pid join writes as t4 on t4.pid  =  t5.pid join author as t1 on t4.aid  =  t1.aid where t1.name  =  "h. v. jagadish";