using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
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 = "!@#$%^&*()-+";
        bool b_numbers=false;
        bool b_lower_case=false;
        bool b_upper_case=false;
        bool b_special = false;
        int char_to_add = 0;
        for (int i=0; i<numbers.Length; i++) 
            if (password.IndexOf(numbers[i])!=-1){
                b_numbers=true;
                break;
            }
        for (int i=0; i<lower_case.Length; i++) 
            if (password.IndexOf(lower_case[i])!=-1){
                b_lower_case=true;
                break;
            }
        for (int i=0; i<upper_case.Length; i++) 
            if (password.IndexOf(upper_case[i])!=-1){
                b_upper_case=true;
                break;
            }
        for (int i=0; i<special_characters.Length; i++) 
            if (password.IndexOf(special_characters[i])!=-1){
                b_special=true;
                break;
            }
        if (!b_numbers) char_to_add++;
        if (!b_lower_case) char_to_add++;
        if (!b_upper_case) char_to_add++;
        if (!b_special) char_to_add++;
        if (password.Length+char_to_add<6) char_to_add+=6-char_to_add-password.Length;
        return char_to_add;
    }

    static void Main(String[] args) {
        int n = Convert.ToInt32(Console.ReadLine());
        string password = Console.ReadLine();
        int answer = minimumNumber(n, password);
        Console.WriteLine(answer);
    }
}