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_16731248_1 (bypass_boosters VARCHAR, spi VARCHAR, exhaust_ports VARCHAR)
### Question:
How many bypass boosters are there on the engine with slit exhaust ports and SPI is yes?
### Answer:
SELECT bypass_boosters FROM table_16731248_1 WHERE spi = "Yes" AND exhaust_ports = "Slit"