main :: IO ()
main = do
  n <- getLine
  s <- getLine
  k <- readLn
  putStrLn $ ans k s
  
ans :: Int -> String -> String
ans k s = let i = s !! (k-1) in okikae i (reverse s) where
  okikae c = foldl (\acc l -> if l == c then c:acc else '*':acc) []