-- Try yukicoder
-- author: Leonardone @ NEETSDKASU

main = interact $ unlines . concat . zipWith ($) [return . show . floor . head, map show . tail] . repeat . solve . map read . words

solve (0:0:0:_) = [-1]
solve (0:0:_:_) = [0]
solve (0:b:c:_) = [1, fromIntegral (-c) / fromIntegral b]
solve (a:0:0:_) = [2, 0]
solve (a:0:c:_) | e < 0     = [0]
                | otherwise = [2, - sqrt e, sqrt e]
                where e = fromIntegral (-c) / fromIntegral a
solve (a:b:0:_) = [2, min 0 x, max 0 x]
                where x = fromIntegral (-b) / fromIntegral a
solve (a:b:c:_) | d < 0  = [0]
                | d == 0 = [1, fromIntegral (-b) / fromIntegral (2*a)]
                | d > 0  = [2, min y z, max y z]
                where d = b * b - 4 * a * c
                      y = (fromIntegral (-b) + sqrt (fromIntegral d)) / fromIntegral (2*a)
                      z = (fromIntegral (-b) - sqrt (fromIntegral d)) / fromIntegral (2*a)
solve _ = undefined