import Control.Applicative
import Control.Monad
import System.IO
import Data.List

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

hasChar :: String -> String -> Int
hasChar x p = if (any (\a -> elem a p) x) then 1 else 0

missing :: String -> Int
missing password = 4 - (hasChar password numbers) - (hasChar password lower_case) - (hasChar password upper_case) - (hasChar password special_characters)

main :: IO ()
main = do
    n_temp <- getLine
    let n = read n_temp :: Int
    password <- getLine
    let m = missing password
    putStrLn $ show (max m (6 - (length password)))