Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.

### Instruction:

Convert text to sql: Return the maximum and minimum number of cities across all markets. | film : film_id , title , studio , director , gross_in_dollar | market : market_id , country , number_cities | film_market_estimation : estimation_id , low_estimate , high_estimate , film_id , type , market_id , year | film_market_estimation.market_id = market.market_id | film_market_estimation.film_id = film.film_id | 

### Response:

select max ( _ ) , min ( _ ) from _ | select max ( number_cities ) , min ( number_cities ) from market