import Data.List
main = do
  [a,b,c] <- map read . words <$> getLine :: IO [Double]
  putStrLn $ show (ans a b c)

ans :: Double -> Double -> Double -> Double
-- x = c / a
-- (2b-2c/a^2)<b
-- (2c/ab)
ans a b c = if b*a*a < 2*c
                then (atan ((2*b*a*a  - 2 * c) / (a ** 3))) / pi * 180
                else (atan (a*b*b/(2*c))) / pi * 180
