
import Control.Applicative
import Control.Monad

main = do
  [n ,k] <- (map read . words) <$> getLine ::IO[Integer]
  xs <- (map read . words) <$> getLine ::IO[Integer]
  putStrLn $ try xs n k 2 
  
  
try xs n k i
 | (maximum (map (`mod` i) xs ) == 0 ) = "IMPOSSIBLE"
 | (maximum xs) < i = "POSSIBLE"
 | otherwise = try xs n k (i+1)

