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 CLASS (prof_num VARCHAR); CREATE TABLE employee (emp_fname VARCHAR, emp_num VARCHAR)
### Question:
Find the first name of the professor who is teaching two courses with code CIS-220 and QM-261.
### Answer:
SELECT T1.emp_fname FROM employee AS T1 JOIN CLASS AS T2 ON T1.emp_num = T2.prof_num WHERE crs_code = 'CIS-220' INTERSECT SELECT T1.emp_fname FROM employee AS T1 JOIN CLASS AS T2 ON T1.emp_num = T2.prof_num WHERE crs_code = 'QM-261'