When the network mask is 255.255.255.128 what is the lowest available subnet?
CREATE TABLE table_149426_4 (
    available_subnets INTEGER,
    network_mask VARCHAR
)
SELECT MIN(available_subnets) FROM table_149426_4 WHERE network_mask = "255.255.255.128"
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: When the network mask is 255.255.255.128 what is the lowest available subnet? ### Input: CREATE TABLE table_149426_4 (
    available_subnets INTEGER,
    network_mask VARCHAR
) ### Response: SELECT MIN(available_subnets) FROM table_149426_4 WHERE network_mask = "255.255.255.128"