What is the grid for dirk heidolf?
CREATE TABLE table_54750 (
    "Rider" text,
    "Manufacturer" text,
    "Laps" real,
    "Time/Retired" text,
    "Grid" real
)
SELECT SUM("Grid") FROM table_54750 WHERE "Rider" = 'dirk heidolf'
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: What is the grid for dirk heidolf? ### Input: CREATE TABLE table_54750 (
    "Rider" text,
    "Manufacturer" text,
    "Laps" real,
    "Time/Retired" text,
    "Grid" real
) ### Response: SELECT SUM("Grid") FROM table_54750 WHERE "Rider" = 'dirk heidolf'