main:: IO ()
main = do
    [a,b] <- (map read . words) <$> getLine
    putStrLn $ solve (a,b)

-- |
--
-- >>> solve (4,5)
-- "Possible"
--
-- >>> solve (1,1)
-- "Impossible"
solve :: (Int, Int) -> String
solve (a,b)
  | any (\x -> x `mod` 3 == 0) [a, b, a+b] = "Possible"
  | otherwise = "Impossible"
