import Control.Applicative
import Data.ByteString.Char8 (ByteString)
import qualified Data.ByteString.Char8 as B
import Data.List
import Data.Char (isSpace)

main :: IO ()
main = solve <$> readLn <*> f >>= prt
  where
    f = readil B.readInt <$> B.getLine

solve :: Int -> [Int] -> (Double, Double, Double)
solve n as = (b, a, c)
  where
    xb = fromIntegral (n - 1) / 2.0
    yb = fromIntegral (sum as) / fromIntegral n
    dxs = map (\x -> fromIntegral x - xb) [0 .. n-1]
    dys = map (\y -> fromIntegral y - yb) as
    a = (sum $ zipWith (*) dxs dys) / (sum $ map (^2) dxs)
    b = yb - a * xb
    f x = a * x + b
    c = sum $ map (^2) $ zipWith (\u v -> u - fromIntegral v) (map (\x -> f (fromIntegral x)) [0 .. n-1]) as

prt :: (Double, Double, Double) -> IO ()
prt (a, b, c) = do
  putStrLn $ show a ++ " " ++ show b
  print c

readil :: Integral a =>  (ByteString -> Maybe (a, ByteString)) -> ByteString -> [a]
readil f = unfoldr g
  where
    g s = do
      (n, s') <- f s
      return (n, B.dropWhile isSpace s')