import qualified Data.ByteString.Char8 as B
import Data.Maybe
main = putStrLn.solve.map(fst.fromJust.B.readInt).B.words=<<B.getLine
solve (a:b:_)
    | or [x`mod`3==0 |x<-[a,b,a+b]] = "Possible"
    | otherwise = "Impossible"