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: Please show the themes of competitions with host cities having populations larger than 1000. | city : city_id , official_name , status , area_km_2 , population , census_ranking | farm : farm_id , year , total_horses , working_horses , total_cattle , oxen , bulls , cows , pigs , sheep_and_goats | farm_competition : competition_id , year , theme , host_city_id , hosts | competition_record : competition_id , farm_id , rank | farm_competition.host_city_id = city.city_id | competition_record.farm_id = farm.farm_id | competition_record.competition_id = farm_competition.competition_id | 

### Response:

select _ from _ where _ | select farm_competition.theme from city join farm_competition on city.city_id = farm_competition.host_city_id where city.population > 1000