Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_149426_4 (prefix_size VARCHAR, network_mask VARCHAR)
### Question:
When the network mask is 255.255.255.252 what is the prefix size?
### Answer:
SELECT prefix_size FROM table_149426_4 WHERE network_mask = "255.255.255.252"