CREATE TABLE table_27116696_1 (production_code VARCHAR, written_by VARCHAR)

What is the total number of production code listings of episodes written by Matthew Lau?
SELECT COUNT(production_code) FROM table_27116696_1 WHERE written_by = "Matthew Lau"
SELECT COUNT("production_code") FROM "table_27116696_1" WHERE "Matthew Lau" = "written_by"