CREATE TABLE table_64995 ("Rank" TEXT, "Nation" TEXT, "Gold" FLOAT, "Silver" FLOAT, "Bronze" FLOAT, "Total" FLOAT)

What was the highest number of gold medals when there were 0 silver medals?
SELECT MAX("Gold") FROM table_64995 WHERE "Silver" < '0'
SELECT MAX("Gold") FROM "table_64995" WHERE "Silver" < '0'