CREATE TABLE table_35336 ("Date" TEXT, "Round" TEXT, "Opponent" TEXT, "Venue" TEXT, "Result" TEXT, "Attendance" FLOAT)

What round has hereford united as the opponent?
SELECT "Round" FROM table_35336 WHERE "Opponent" = 'hereford united'
SELECT "Round" FROM "table_35336" WHERE "Opponent" = 'hereford united'