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 trained_in (physician VARCHAR, treatment VARCHAR); CREATE TABLE procedures (cost INTEGER, code VARCHAR); CREATE TABLE physician (employeeid VARCHAR, name VARCHAR)
### Question:
What is the average cost of procedures that physician John Wen was trained in?
### Answer:
SELECT AVG(T3.cost) FROM physician AS T1 JOIN trained_in AS T2 ON T1.employeeid = T2.physician JOIN procedures AS T3 ON T3.code = T2.treatment WHERE T1.name = "John Wen"