import java.util.HashSet;
import java.util.Locale;
import java.util.Scanner;
import java.util.Set;

public class StrongPassword {

    public static void main(String[] args) {
        try(Scanner in = new Scanner(System.in)){
            in.useLocale(Locale.ENGLISH);
            Set<Character> numbers = toSet("0123456789".toCharArray());
            Set<Character> lower_case = toSet("abcdefghijklmnopqrstuvwxyz".toCharArray());
            Set<Character> upper_case = toSet("ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray());
            Set<Character> special_characters = toSet("!@#$%^&*()-+".toCharArray());

            int n = in.nextInt();
            char[] pwd = in.next().toCharArray();
            boolean number = false;
            boolean lower = false;
            boolean upper = false;
            boolean special = false;
            for (int i=0; i<pwd.length; i++){
                if (numbers.contains(pwd[i])){
                    number = true;
                }
                if (lower_case.contains(pwd[i])){
                    lower = true;
                }
                if (upper_case.contains(pwd[i])){
                    upper = true;
                }
                if (special_characters.contains(pwd[i])){
                    special = true;
                }
            }
            int diff = 0;
            if (!number){
                diff++;
            }
            if (!lower){
                diff++;
            }
            if (!upper){
                diff++;
            }
            if (!special){
                diff++;
            }
            if (n+diff<6){
                System.out.println(6-n);
            } else {
                System.out.println(diff);
            }
        }
    }

    private static Set<Character> toSet(char[] numbers) {
        Set<Character> numbersSet = new HashSet<>();
        for (char number : numbers) {
            numbersSet.add(number);
        }
        return numbersSet;
    }
}