import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    static int minimumNumber(int n, String password) {
        boolean digit = false, lower= false, upper= false, special= false;
        for(int i = 0; i < password.length(); ++i) {
            char c = password.charAt(i);
            if(Character.isUpperCase(c)) upper = true;
            else if(Character.isLowerCase(c)) lower = true;
            else if(Character.isDigit(c)) digit = true;
            else if("!@#$%^&*()-+".indexOf(c) != -1) special = true;
            if(upper && lower && digit && special) break;
        }
        int count = 0;
        if(!upper) count++;
        if(!lower) count++;
        if(!digit) count++;
        if(!special) count++;
        return password.length()+count < 6 ? 6-password.length(): count;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        String password = in.next();
        int answer = minimumNumber(n, password);
        System.out.println(answer);
        in.close();
    }
}