import Control.Applicative
import Control.Monad
import System.IO


main :: IO ()
main = do
    n_temp <- getLine
    let n = read n_temp :: Int
    password <- getLine
    let sats = map (\chrs -> isSat chrs password) [numbers, lower_case, upper_case, special_characters]
        len = length (filter (not) sats)
        pLen = length password
    print $ if len + pLen >= 6
               then len
               else 6 - pLen

isSat :: [Char] -> String -> Bool
isSat chrs = or . map (`elem` chrs)

numbers = "0123456789"
lower_case = "abcdefghijklmnopqrstuvwxyz"
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
special_characters = "!@#$%^&*()-+"