CREATE TABLE table_63752 ("Heat" FLOAT, "Lane" FLOAT, "Name" TEXT, "Nationality" TEXT, "Time" TEXT)

What's Sara Isakovi 's lane number that had a heat of 3?
SELECT SUM("Lane") FROM table_63752 WHERE "Heat" = '3' AND "Name" = 'sara isakovič'
SELECT SUM("Lane") FROM "table_63752" WHERE "Heat" = '3' AND "Name" = 'sara isakovič'