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

public class Solution {

    static int minimumNumber(int n, String password) {
        //numbers = "0123456789";
        //lower_case = "abcdefghijklmnopqrstuvwxyz";
        ///upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        //special_characters = "!@#$%^&*()-+";
        HashSet<Character> hs= new HashSet<Character>();
        hs.add('!');
        hs.add('@');
        hs.add('#');
        hs.add('$');
        hs.add('%');
        hs.add('^');
        hs.add('&');
        hs.add('*');
        hs.add('(');
        hs.add(')');
        hs.add('-');
        hs.add('+');
        int valid=0;
        int req=0;
        int digit=0,lower=0,upper=0,special=0;
        for(int i=0;i<password.length();i++){
            if(Character.isDigit(password.charAt(i)))
               digit++;
             else if(hs.contains(password.charAt(i)))
               special++;
             else if(Character.isUpperCase(password.charAt(i)))
               upper++;
             else if(Character.isLowerCase(password.charAt(i)))
               lower++;
        }
        if(digit==0)
            req++;
        if(lower==0)
            req++;
        if(upper==0)
            req++;
        if(special==0)
            req++;
        if(n+req<6)
            req+=6-(n+req);
        return req;

    }

    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();
    }
}