What is the name of the 1st Party that has a 3rd Party of Unionist, and 2nd Member of Sir John Boyd-Orr?
CREATE TABLE "members_of_parliament" (
  "election" text,
  "1st_member" text,
  "1st_party" text,
  "2nd_member" text,
  "2nd_party" text,
  "3rd_member" text,
  "3rd_party" text
);
SELECT "1st_party" FROM "members_of_parliament" WHERE "3rd_party"='unionist' AND "2nd_member"='sir john boyd-orr';