CREATE TABLE table_59639 ("Team" TEXT, "Driver" TEXT, "Class" TEXT, "Chassis" TEXT, "Engine" TEXT, "Rounds" TEXT)

How many rounds did satrio hermanto go with an opc-challenge engine?
SELECT "Rounds" FROM table_59639 WHERE "Engine" = 'opc-challenge' AND "Driver" = 'satrio hermanto'
SELECT "Rounds" FROM "table_59639" WHERE "Driver" = 'satrio hermanto' AND "Engine" = 'opc-challenge'