What is the smallest electorate for the Conservative party in South West Devon constituency, with over 2 conservatives and a name of Plymstock Radford?
CREATE TABLE "wards" (
  "name" text,
  "labour" real,
  "conservative" real,
  "political_party" text,
  "electorate" real,
  "constituency" text
);
SELECT MIN("electorate") FROM "wards" WHERE "political_party"='conservative' AND "constituency"='south west devon' AND "conservative">2 AND "name"='plymstock radford';