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 pattern1 = "[a-z]";
        String pattern2 = "[0-9]+";
        String pattern3 = "[A-Z]+";
        String pattern4 = "[!@#$%\\^&*()\\-+]+";
        int added = 0;
        if(Pattern.compile(pattern1).matcher(password).find()) {
        }else {
            added++;
        }
        if(Pattern.compile(pattern2).matcher(password).find()) {
        }else {
            added++;
        }
        if(Pattern.compile(pattern3).matcher(password).find()) {
        }else {
            added++;
        }
        if(Pattern.compile(pattern4).matcher(password).find()) {
        }else {
            added++;
        }
        return (password.length() + added > 6 ?added :6 - password.length());
    }

    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();
    }
}