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

    static bool Contains(string symbols, string password){
        bool contains = false;
        
        for(int j = 0; j < password.Length; j++)
        {
            for(int i = 0; i < symbols.Length; i++)
            {
                    if(symbols[i] == password[j])
                    {
                        contains = true;
                        return contains;
                    }
            }
        }
        
        return contains;
    }
    
    static int minimumNumber(int n, string password) {
        List<string> symbols = new List<string>();
        symbols.Add("0123456789");
        symbols.Add("abcdefghijklmnopqrstuvwxyz");
        symbols.Add("ABCDEFGHIJKLMNOPQRSTUVWXYZ");
        symbols.Add("!@#$%^&*()-+");
        int minimumNumber = 0;
        
        for(int i = 0; i < symbols.Count; i++)
        {
            if(!Contains(symbols[i], password))
            {
                minimumNumber++;
            }
        }
        
        if(password.Length + minimumNumber < 6)
        {
            minimumNumber += 6 - (password.Length + minimumNumber);
        }
        
        return minimumNumber;
    }

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