What is the transfer window with n/a as the Transfer fee, free agent for the Moving to, and Joe Sagar as the name?
CREATE TABLE table_51977 (
    "Nat." text,
    "Name" text,
    "Moving to" text,
    "Type" text,
    "Transfer window" text,
    "Transfer fee" text
)
SELECT "Transfer window" FROM table_51977 WHERE "Transfer fee" = 'n/a' AND "Moving to" = 'free agent' AND "Name" = 'joe sagar'
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 transfer window with n/a as the Transfer fee, free agent for the Moving to, and Joe Sagar as the name? ### Input: CREATE TABLE table_51977 (
    "Nat." text,
    "Name" text,
    "Moving to" text,
    "Type" text,
    "Transfer window" text,
    "Transfer fee" text
) ### Response: SELECT "Transfer window" FROM table_51977 WHERE "Transfer fee" = 'n/a' AND "Moving to" = 'free agent' AND "Name" = 'joe sagar'