What is the Authority for Kuranui Primary School that is located in the Area of Tirau?
CREATE TABLE "south_waikato_district" (
  "name" text,
  "years" text,
  "gender" text,
  "area" text,
  "authority" text,
  "decile" real,
  "roll" text
);
SELECT "authority" FROM "south_waikato_district" WHERE "area"='tirau' AND "name"='kuranui primary school';