import Data.Maybe
import Control.Monad
import qualified Data.ByteString.Char8 as C

readInt' = fst.fromJust.C.readInt
readLnInt = map readInt'.C.words<$>C.getLine
readCsInt n = concat<$>replicateM n readLnInt

main = do
 [n] <- readLnInt
 s <- getLine
 putStr $ solve n s

solve n s
 | (length s) < n = s
 | otherwise = (take n s) ++ "..."
