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 accelerator_compatible_browser (id VARCHAR, accelerator_id VARCHAR); CREATE TABLE web_client_accelerator (id VARCHAR, accelerator_id VARCHAR)
### Question:
How many accelerators are not compatible with the browsers listed ?
### Answer:
SELECT COUNT(*) FROM web_client_accelerator WHERE NOT id IN (SELECT accelerator_id FROM accelerator_compatible_browser)