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) {
        // Return the minimum number of characters to make the password strong
        String numbers = "0123456789";
        String lower_case = "abcdefghijklmnopqrstuvwxyz";
        String upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        String special_characters = "!@#$%^&*()-+";
        int minNum = 0;
        for (int i = 0; i < numbers.length(); i++) {
            if (password.contains(Character.toString(numbers.charAt(i)))) {
                break;
            }
            if (i==numbers.length()-1) {
                minNum++;
            }
        }
        for (int i = 0; i < lower_case.length(); i++) {
            if (password.contains(Character.toString(lower_case.charAt(i)))) {
                break;
            } 
            if (i==lower_case.length()-1) {
                minNum++;
            }
        }
        for (int i = 0; i < upper_case.length(); i++) {
            if (password.contains(Character.toString(upper_case.charAt(i)))) {
                break;
            } 
            if (i==upper_case.length()-1) {
                minNum++;
            }
        }
        for (int i = 0; i < special_characters.length(); i++) {
            if (password.contains(Character.toString(special_characters.charAt(i)))) {
                break;
            } 
            if (i==special_characters.length()-1) {
                minNum++;
            }
        }
        if ((minNum+n)<6) minNum = minNum + (6-n-minNum);
        return minNum;
    }

    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();
    }
}