CREATE TABLE table_48792 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Attendance" TEXT)

What is the total number of weeks that the buffalo bills played against the San Diego Chargers?
SELECT SUM("Week") FROM table_48792 WHERE "Opponent" = 'san diego chargers'
SELECT SUM("Week") FROM "table_48792" WHERE "Opponent" = 'san diego chargers'