how many millions of north american viewers had the episode called "smother"? 
CREATE TABLE "table1_28358487_3" (
  "no" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "u_s_viewers_million" text,
  "original_air_date" text,
  "production_code" real
);
SELECT "u_s_viewers_million" FROM "table1_28358487_3" WHERE "title"='\"Smother\"';