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

public class Solution {
    private final static char[] numbers = "0123456789".toCharArray();
    private final static char[] lower_case = "abcdefghijklmnopqrstuvwxyz".toCharArray();
    private final static char[] upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
    private final static char[] special_characters = "!@#$%^&*()-+".toCharArray();

    private static boolean contains(char[] chars, char c) {
        for (int i = 0; i < chars.length; i++) {
            if (chars[i] == c) return true;
        }
        return false;
    }
    
    static int minimumNumber(int n, String password) {
        int a = Math.max(6 - password.length(), 0);
        int b = 0;
        for (int i = 0; i < password.length(); i++) {
            if (contains(numbers, password.charAt(i))) {
                b--;
                break;
            }
        }
        b++;
        
        for (int i = 0; i < password.length(); i++) {
            if (contains(lower_case, password.charAt(i))) {
                b--;
                break;
            }
        }
        b++;
        
        for (int i = 0; i < password.length(); i++) {
            if (contains(upper_case, password.charAt(i))) {
                b--;
                break;
            }
        }
        b++;
        
        for (int i = 0; i < password.length(); i++) {
            if (contains(special_characters, password.charAt(i))) {
                b--;
                break;
            }
        }
        b++;
        
        return Math.max(a, b);
    }

    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();
    }
}