the episode "a change in heart/pants" had a maximum of what number in the series?
CREATE TABLE "table1_27913766_1" (
  "series_num" real,
  "season_num" real,
  "title" text,
  "written_by" text,
  "original_air_date" text,
  "u_s_viewers_millions" text
);
SELECT MAX("series_num") FROM "table1_27913766_1" WHERE "title"='\"A Change in Heart/Pants\"';