What are the number of days in 1945 where the constituent was heywood and radcliffe?
CREATE TABLE "since_1945" (
  "candidate" text,
  "party" text,
  "constituency" text,
  "year" text,
  "days" text
);
SELECT "days" FROM "since_1945" WHERE "year"='1945' AND "constituency"='heywood and radcliffe';