CREATE TABLE table_13043 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Attendance" TEXT)

In what week(s) did the Broncos go up against the Cleveland Browns?
SELECT SUM("Week") FROM table_13043 WHERE "Opponent" = 'cleveland browns'
SELECT SUM("Week") FROM "table_13043" WHERE "Opponent" = 'cleveland browns'