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) {
        String numbers = "0123456789";
        String lower_case = "abcdefghijklmnopqrstuvwxyz";
        String upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        String special_characters = "!@#$%^&*()-+";
        boolean length = false;
        boolean num = false;
        boolean low = false;
        boolean up = false;
        boolean special = false;
        
        if (password.length() >= 6) length = true;
        
        for (int i = 0; i < password.length(); i++) {
            for (int e = 0; e < numbers.length(); e++) {
                if (password.substring(i, i+1).equals(numbers.substring(e, e+1))) num = true;
            }
            for (int e = 0; e < lower_case.length(); e++) {
                if (password.substring(i, i+1).equals(lower_case.substring(e, e+1))) low = true;
            }
            for (int e = 0; e < upper_case.length(); e++) {
                if (password.substring(i, i+1).equals(upper_case.substring(e, e+1))) up = true;
            }
            for (int e = 0; e < special_characters.length(); e++) {
                if (password.substring(i, i+1).equals(special_characters.substring(e, e+1))) special = true;
            }
        }
        
        int count = 0;
        int extra = 0;
        
        if (!length) {
            count = 6 - password.length();
            extra = 6 - password.length();
        }
        if (!num)
            if (extra != 0) extra--;
            else count++;
        if (!low)
            if (extra != 0) extra--;
            else count++;
        if (!up) 
            if (extra != 0) extra--;
            else count++;
        if (!special) {
            if (extra != 0) extra--;
            else count++;
        }
        
        return 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();
    }
}