How many introductory phrases were there on David Finkel's guest episode?
CREATE TABLE "table1_25691838_8" (
  "episode_num" real,
  "the_w_rd" text,
  "guest" text,
  "introductory_phrase" text,
  "original_airdate" text,
  "production_code" real
);
SELECT COUNT("introductory_phrase") FROM "table1_25691838_8" WHERE "guest"='David Finkel';