main :: IO ()
main = do
    [a,b] <- map read . words <$> getLine
    print $ solve a b

solve :: Int -> Int -> Double
solve a b = if a - b == 0 then 0 else fromRational result
    where a1 = toRational a
          b1 = toRational b
          dx = (b1 - a1) / 10000
          f x = abs $ (x - a1) * (x - b1) * dx
          result = sum $ map f [a1,a1+dx..b1]