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 = "!@#$%^&*()-+";
        
        boolean num = false;
        boolean l = false;
        boolean u = false;
        boolean s = false;
        
        for (char c : password.toCharArray()) {
            if (!num && numbers.indexOf(c) >= 0) {
                num = true;
            } else if (!l && lower_case.indexOf(c) >= 0) {
                l = true;
            } else if (!u && upper_case.indexOf(c) >= 0) {
                u = true;
            } else if (!s && special_characters.indexOf(c) >= 0) {
                s = true;
            }
        }
        
        int count = 0;
        
        if (!num) {
            count++;
        }
        if (!l) {
            count++;
        }
        if (!u) {
            count++;
        }
        if (!s) {
            count++;
        }
        
        if (n + count < 6) {
            count = 6-n;
        }
        
        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();
    }
}