What is the total launch failures when there are 4 launches, and the not usable is greater than 0?
CREATE TABLE table_40905 (
    "Block" text,
    "Launched" real,
    "Operational" real,
    "Not usable" real,
    "Retired" real,
    "Launch Failures" real
)
SELECT SUM("Launch Failures") FROM table_40905 WHERE "Launched" = '4' AND "Not usable" > '0'
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 total launch failures when there are 4 launches, and the not usable is greater than 0? ### Input: CREATE TABLE table_40905 (
    "Block" text,
    "Launched" real,
    "Operational" real,
    "Not usable" real,
    "Retired" real,
    "Launch Failures" real
) ### Response: SELECT SUM("Launch Failures") FROM table_40905 WHERE "Launched" = '4' AND "Not usable" > '0'