how many different countries won at least one stage in the 1964 tour de france ?
CREATE TABLE table_203_44 (
    id number,
    "stage" text,
    "date" text,
    "route" text,
    "terrain" text,
    "length" text,
    "winner" text
)
SELECT COUNT(DISTINCT "winner") FROM table_203_44
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: how many different countries won at least one stage in the 1964 tour de france ? ### Input: CREATE TABLE table_203_44 (
    id number,
    "stage" text,
    "date" text,
    "route" text,
    "terrain" text,
    "length" text,
    "winner" text
) ### Response: SELECT COUNT(DISTINCT "winner") FROM table_203_44