Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE authorship (authid VARCHAR, paperid VARCHAR)
TABLE: CREATE TABLE authors (lname VARCHAR, fname VARCHAR, authid VARCHAR)
TABLE: CREATE TABLE papers (paperid VARCHAR)

### Question ###
What is the last name of the author that has published the most papers?

### Accurate SQL ###

SELECT t1.lname FROM authors AS t1 JOIN authorship AS t2 ON t1.authid = t2.authid JOIN papers AS t3 ON t2.paperid = t3.paperid GROUP BY t1.fname, t1.lname ORDER BY COUNT(*) DESC LIMIT 1