What was round of 64 of the singles event when the result of round 16 was did not advance and the athlete was Iveta Benešová?
CREATE TABLE "table1_17289604_38" (
  "athlete" text,
  "event" text,
  "round_of_64" text,
  "round_of_32" text,
  "round_of_16" text,
  "quarterfinals" text
);
SELECT "round_of_64" FROM "table1_17289604_38" WHERE "event"='Singles' AND "round_of_16"='Did not advance' AND "athlete"='Iveta Benešová';