import Data.List.Split
import Data.Maybe
import qualified Data.ByteString.Char8 as B
main=mapM_(putStrLn.solve).chunksOf 2.map(map(fst.fromJust.B.readInt).B.words).B.lines=<<B.getContents
solve[[n,k],as]=if k<=maximum as && 0==k`mod`foldr1 gcd as then "POSSIBLE" else "IMPOSSIBLE"