What is the Class for the ERP W of more than 2 and the call sign of w223au?
CREATE TABLE "translators" (
  "call_sign" text,
  "frequency_m_hz" real,
  "city_of_license" text,
  "erp_w" real,
  "class" text,
  "fcc_info" text
);
SELECT "class" FROM "translators" WHERE "erp_w">2 AND "call_sign"='w223au';