{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE MultiWayIf #-}


import Control.Arrow
import Control.Concurrent
import Control.Monad
import qualified Data.ByteString.Char8 as C
import Data.Complex
import Data.Function
import Data.Function.HT
import qualified Data.IntMap.Strict as IM
import qualified Data.IntSet as IS
import Data.List
import Data.Ord
import qualified Data.Sequence as Sq
import Data.Vector.Algorithms.Search
import qualified Data.Vector as V
import qualified Data.Vector.Mutable as VM
import qualified Data.Vector.Unboxed as U
import qualified Data.Vector.Unboxed.Mutable as UM
import Debug.Trace


------------------
-- #   Read   # --
------------------

r :: Int -> IO (U.Vector Int)
r n = U.unfoldrN n (C.readInt . C.dropWhile (==' ')) <$> C.getLine

r' :: IO [Int]
r'  =   unfoldr    (C.readInt . C.dropWhile (==' ')) <$> C.getLine



main :: IO ()
main = do
    n <- readLn :: IO Int
    as <- map fromIntegral <$> r' :: IO [Integer]
    let x = product as
    print $ if x > 10^18 then -1 else x
