using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution {

    static int minimumNumber(int n, string password) {
        string numbers = "0123456789";
        string lower_case = "abcdefghijklmnopqrstuvwxyz";
        string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        string special_characters = "!@#$%^&*()-+";
        
        int count=0;
        if(!numbers.ToCharArray().Any(password.Contains))
            count++;
        if(!lower_case.ToCharArray().Any(password.Contains))
            count++;
        if(!upper_case.ToCharArray().Any(password.Contains))
            count++;
        if(!special_characters.ToCharArray().Any(password.Contains))
            count++;
        return Math.Max(6-n,count);
    }

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