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

    static int minimumNumber(int n, string password) {
        var r = 0;

        if (!Regex.IsMatch(password, @"[0-9]")) r++;
        if (!Regex.IsMatch(password, @"[a-z]")) r++;
        if (!Regex.IsMatch(password, @"[A-Z]")) r++;

        var special = false;
        var chars = new List<Char> {'!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '-', '+'};
        if (!chars.Intersect(password).Any()) r++;

        var x = password.Length + r;
        if (x >= 6) return r;
        else return r + 6 - x;
    }

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