When driver heinz-harald frentzen has a number of laps greater than 60, what is the sum of grid?
CREATE TABLE table_name_51 (
    grid VARCHAR,
    laps VARCHAR,
    driver VARCHAR
)
SELECT COUNT(grid) FROM table_name_51 WHERE laps > 60 AND driver = "heinz-harald frentzen"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: When driver heinz-harald frentzen has a number of laps greater than 60, what is the sum of grid? ### Input: CREATE TABLE table_name_51 (
    grid VARCHAR,
    laps VARCHAR,
    driver VARCHAR
) ### Response: SELECT COUNT(grid) FROM table_name_51 WHERE laps > 60 AND driver = "heinz-harald frentzen"