import Control.Applicative
import Data.Bool (bool)

main :: IO ()
main = solve <$> f >>= mapM_ print
  where
    f = map read <$> words <$> getLine

solve :: [Int] -> [Int]
solve [a, b, c] = bool ys [-1] $ null ys
  where
    xs = if (b + c) `mod` a == 0 then [(b + c) `div` a] else []
    ys = if c `mod` a == 0 && b >= c then (c `div` a) : xs else xs