CREATE TABLE table_name_91 (grid INT, laps VARCHAR, driver VARCHAR)

What is the grid total for alain prost with over 14 laps?
SELECT SUM(grid) FROM table_name_91 WHERE laps > 14 AND driver = "alain prost"
SELECT SUM("grid") FROM "table_name_91" WHERE "alain prost" = "driver" AND "laps" > 14