using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication12
{
    class Program

    {
        static int minimumNumber(int n,List<char> password)
        {
            int sum = 0;
           List<char> numbers = "0123456789".ToList();
           List<char> lower_case = "abcdefghijklmnopqrstuvwxyz".ToList();
           List<char> upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".ToList();
           List<char> special_characters = "!@#$%^&*()-+".ToList();
           int[] conter = new int[4];
            var exists=true;
           for (int i = 0; i < numbers.Count(); i++)
           {
               exists = password.Contains(numbers[i]);
               if (exists == true)
               {
                   conter[0]++;
               }
           }

           for (int i = 0; i < lower_case.Count(); i++)
           {
                exists = password.Contains(lower_case[i]);
               if (exists == true)
               {
                   conter[1]++;
               }
           }
           for (int i = 0; i < upper_case.Count(); i++)
           {
                exists = password.Contains(upper_case[i]);
               if (exists == true)
               {
                   conter[2]++;
               }
           }
           for (int i = 0; i < special_characters.Count(); i++)
           {
                exists = password.Contains(special_characters[i]);
               if (exists == true)
               {
                   conter[3]++;
               }
           }
           for (int i = 0; i < 4; i++)
           {
               if (conter[i] > 0)
               {
                   sum++;
               }

           }
           
            int answer=0;
            if (n < 6)
            {
                
                
                if (sum==4)
                {
                    answer = 6 - n;
                }
                else 
                {
                    int sure_sum = 0;
                    sure_sum = 4 - sum;
                    if ((sure_sum + n)<6)
                    {
                        answer = 6 - (sure_sum + n);
                        answer = answer + sure_sum;
                    }
                    else
                    {
                        answer = sure_sum;
                    }
                    
                }
               

            }
            else
            {
                
                
                for (int i = 0; i < conter.Length; i++)
                {
                    if (conter[i] == 0)
                    {
                        answer++;
                    }
                }

            }

            return answer;
        }
        static void Main(string[] args)
        {
            List<char> pass = new List<char>();
            int n = Convert.ToInt32(Console.ReadLine());
            if (n >= 1 && n <= 100)
            {
                string password = Console.ReadLine();
                pass = password.ToList<char>();
                int answer = minimumNumber(n, pass);
                Console.WriteLine(answer);
            }
        }
    }
}