using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution {
    
    static bool isStringContainString(string toCompare, string comparer)
    {
        var parts = comparer.ToCharArray().ToList();
        return parts.Any(_=> toCompare.Contains(_));
    }
    
    static int minimumNumber(int n, string password) {
       string numbers = "0123456789";
       string lower_case = "abcdefghijklmnopqrstuvwxyz";
       string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
       string special_characters = "!@#$%^&*()-+";
       
        int ans = 0;
        if(!isStringContainString(password, numbers)) ans++;
        if(!isStringContainString(password, lower_case)) ans++;
        if(!isStringContainString(password, upper_case)) ans++;
        if(!isStringContainString(password, special_characters)) ans++;
        if(ans+password.Length < 6) {
            int diff = (6-password.Length);
            if(diff>ans) return diff;
            else return ans;
        }
        return ans;
    }

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