Who's the winner in stage 1a, where the leader in the young rider classification is Francesco Casagrande?
CREATE TABLE table_17564 (
    "Stage" text,
    "Winner" text,
    "General classification" text,
    "Points classification" text,
    "Mountains classification" text,
    "Young rider classification" text,
    "Intergiro classification" text,
    "Trofeo Fast Team" text
)
SELECT "Winner" FROM table_17564 WHERE "Young rider classification" = 'Francesco Casagrande' AND "Stage" = '1a'
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: Who's the winner in stage 1a, where the leader in the young rider classification is Francesco Casagrande? ### Input: CREATE TABLE table_17564 (
    "Stage" text,
    "Winner" text,
    "General classification" text,
    "Points classification" text,
    "Mountains classification" text,
    "Young rider classification" text,
    "Intergiro classification" text,
    "Trofeo Fast Team" text
) ### Response: SELECT "Winner" FROM table_17564 WHERE "Young rider classification" = 'Francesco Casagrande' AND "Stage" = '1a'