What's the points classification of Stage 18 when the general classification was Denis Menchov?
CREATE TABLE table_name_46 (
    points_classification VARCHAR,
    general_classification VARCHAR,
    stage VARCHAR
)
SELECT points_classification FROM table_name_46 WHERE general_classification = "denis menchov" AND stage = "18"
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's the points classification of Stage 18 when the general classification was Denis Menchov? ### Input: CREATE TABLE table_name_46 (
    points_classification VARCHAR,
    general_classification VARCHAR,
    stage VARCHAR
) ### Response: SELECT points_classification FROM table_name_46 WHERE general_classification = "denis menchov" AND stage = "18"