Table schema:
CREATE TABLE Staff (staff_address_id VARCHAR); CREATE TABLE Addresses (city VARCHAR, address_id VARCHAR)

Question: Which city lives most of staffs? List the city name and number of staffs.
SQL: SELECT T1.city, COUNT(*) FROM Addresses AS T1 JOIN Staff AS T2 ON T1.address_id = T2.staff_address_id GROUP BY T1.city ORDER BY COUNT(*) DESC LIMIT 1