CREATE TABLE table_21790 ("Rank" FLOAT, "Country" CLOB, "Miss United Continent" FLOAT, "Virreina" FLOAT, "1st RU" FLOAT, "2nd RU" FLOAT, "3rd RU" FLOAT, "4th RU" FLOAT, "Semifinalists" FLOAT, "Total" FLOAT)

How many 3rd ru does Costa Rica have?
SELECT MAX("3rd RU") FROM table_21790 WHERE "Country" = 'Costa Rica'
SELECT MAX("3rd RU") FROM "table_21790" WHERE "Country" = 'Costa Rica'