When birkenhead is the city/town and merseyside is the county and england is the country how many ranks are there?
CREATE TABLE "cities_and_towns" (
  "rank" real,
  "city_town" text,
  "county" text,
  "region_province" text,
  "population" real,
  "country" text
);
SELECT COUNT("rank") FROM "cities_and_towns" WHERE "country"='England' AND "county"='Merseyside' AND "city_town"='Birkenhead';