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

    static int minimumNumber(int n, string password)
    {
        const string numbers = "0123456789";
        const string lowerCase = "abcdefghijklmnopqrstuvwxyz";
        const string upperCase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        const string specialCharacters = "!@#$%^&*()-+";

        var hasNumbers = false;
        var hasLowerCase = false;
        var hasUpperCase = false;
        var hasSpecialCharacters = false;
        var toAdd = 0;
        for (var i = 0; i < n; i++)
        {
            var c = password[i];
            if (numbers.Contains(c)) hasNumbers = true;
            if (lowerCase.Contains(c)) hasLowerCase = true;
            if (upperCase.Contains(c)) hasUpperCase = true;
            if (specialCharacters.Contains(c)) hasSpecialCharacters = true;
        }

        if (!hasNumbers) toAdd++;
        if (!hasLowerCase) toAdd++;
        if (!hasUpperCase) toAdd++;
        if (!hasSpecialCharacters) toAdd++;

        if (n + toAdd < 6) return 6 - n;
        return toAdd;
    }

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