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

public class Solution
{
    public static void main(String[] args)
    {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        String password = in.next();
        int add = 0;
        /*
        if (!password.matches(".*[A-Z]+.*"))
            add++;
        if (!password.matches(".*[a-z]+.*"))
            add++;
        if (!password.matches(".*[\\d]+.*"))
            add++;
        if (!password.matches(".*[!@#$%^&*()-+]+.*"))
            add++;
        */
        String special = "!@#$%^&*()-+";
        
        code: {
            for (int i = 0; i < 26; i++)
                if (password.contains("" + (char) ('A' + i)))
                    break code;
            add++;
        }
        code: {
            for (int i = 0; i < 26; i++)
                if (password.contains("" + (char) ('a' + i)))
                    break code;
            add++;
        }
        code: {
            for (int i = 0; i < 10; i++)
                if (password.contains("" + (char) ('0' + i)))
                    break code;
            add++;
        }
        code: {
            for (int i = 0; i < special.length(); i++)
                if (password.contains("" + special.charAt(i)))
                    break code;
            add++;
        }
        
        System.out.println(Math.max(add, 6 - n));
        in.close();
    }
}