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 = "!@#$%^&*()-+";

        int count = 0;

        boolean criteria = false;
        for(int i=0;i<numbers.length();i++) {
            if(password.contains(numbers.charAt(i)+"")) {
                criteria = true;
                break;
            }
        }

        if(!criteria) {
            count++;
        }

        criteria = false;
        for(int i=0;i<lower_case.length();i++) {
            if(password.contains(lower_case.charAt(i)+"")) {
                criteria = true;
                break;
            }
        }

        if(!criteria) {
            count++;
        }

        criteria = false;
        for(int i=0;i<upper_case.length();i++) {
            if(password.contains(upper_case.charAt(i)+"")) {
                criteria = true;
                break;
            }
        }

        if(!criteria) {
            count++;
        }


        criteria = false;
        for(int i=0;i<special_characters.length();i++) {
            if(password.contains(special_characters.charAt(i)+"")) {
                criteria = true;
                break;
            }
        }

        if(!criteria) {
            count++;
        }

        if(password.length() + count < 6) {
            count+=(6-(password.length()+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();
    }
}