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
        int charNeed = 0;
        bool hasDigit = password.Any(x => Char.IsDigit(x));
        bool hasLower = password.Any(x => Char.IsLower(x));
        bool hasUpper = password.Any(x => Char.IsUpper(x));
        bool hasSpecial = password.Any(x => "!@#$%^&*()-+".Contains(x));
        
        if (!hasDigit) charNeed++;
        if (!hasLower) charNeed++;
        if (!hasUpper) charNeed++;
        if (!hasSpecial) charNeed++;
        
        int len = password.Length;
        
        if (len >= 6)
        {
            return charNeed;
        }
        else
        {
            return Math.Max(6 - len, charNeed);
        }
    }

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