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

    static int minimumNumber(int n, string password) {
        var numbers = "0123456789";
        var lower_case = "abcdefghijklmnopqrstuvwxyz";
        var upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        var special_characters = "!@#$%^&*()-+";
        
        int[] rules = new int[4];
        
        for(int i = 0; i < n; i++){            
            if(numbers.Contains(password[i])){
                rules[0]++;
            } else if (lower_case.Contains(password[i])){
                rules[2]++;
            } else if (upper_case.Contains(password[i])){
                rules[1]++;
            } else if (special_characters.Contains(password[i])){
                rules[3]++;
            }            
        }
        var requiredChar = rules.Count(r => r == 0);
        var totalChar = requiredChar + n;
        
        if(totalChar > 6)
            return requiredChar;
        else 
            return requiredChar + (6-totalChar);
    }

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