CREATE TABLE inst (instid VARCHAR(255), name VARCHAR(255)); CREATE TABLE authorship (paperid VARCHAR(255), instid VARCHAR(255)); CREATE TABLE papers (title VARCHAR(255), paperid VARCHAR(255))
Find the number of papers published by the institution "University of Pennsylvania".
    
SQL: SELECT COUNT(DISTINCT t1.title) FROM papers AS t1 JOIN authorship AS t2 ON t1.paperid = t2.paperid JOIN inst AS t3 ON t2.instid = t3.instid WHERE t3.name = "University of Pennsylvania"