Find the names of districts where have both city mall and village store type stores.
select t3.district_name from store as t1 join store_district as t2 on t1.store_id = t2.store_id join district as t3 on t2.district_id = t3.district_id where t1.type = "City Mall" intersect select t3.district_name from store as t1 join store_district as t2 on t1.store_id = t2.store_id join district as t3 on t2.district_id = t3.district_id where t1.type = "Village Store"