import Control.Applicative
import Data.Bool (bool)

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

solve :: [Int] -> String
solve [a, b] = bool "Impossible" "Possible" $ any (== 0) $ map (flip mod 3) [a, b, a + b]
