What is the final score of the 1st round game of club Union Luxembourg?
CREATE TABLE table_6664 (
    "Season" text,
    "Competition" text,
    "Round" text,
    "Club" text,
    "Score" text
)
SELECT "Score" FROM table_6664 WHERE "Round" = '1st round' AND "Club" = 'union luxembourg'
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 final score of the 1st round game of club Union Luxembourg? ### Input: CREATE TABLE table_6664 (
    "Season" text,
    "Competition" text,
    "Round" text,
    "Club" text,
    "Score" text
) ### Response: SELECT "Score" FROM table_6664 WHERE "Round" = '1st round' AND "Club" = 'union luxembourg'