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 AssignedTo (ssn VARCHAR, scientist VARCHAR); CREATE TABLE scientists (ssn VARCHAR, scientist VARCHAR)
### Question:
Find the number of scientists who are not assigned to any project.
### Answer:
SELECT COUNT(*) FROM scientists WHERE NOT ssn IN (SELECT scientist FROM AssignedTo)