CREATE TABLE Staff (staff_address_id VARCHAR(255)); CREATE TABLE Addresses (city VARCHAR(255), address_id VARCHAR(255))
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