import java.io.*;
import java.util.Scanner;
class HackerRank_Strong_Password
{
    public static void main(String args[]) throws IOException
    {
        try
        {
            Scanner sc = new Scanner (System.in) ;
            int n , i , capital = 0 , small = 0 , digit = 0 , special = 0 , c = 0  ;
            String str ;
            char ch ;
            n = sc.nextInt() ;
            sc.nextLine() ;
            str = sc.nextLine() ;
            for(i = 0 ; i < n ; i++)
            {
                ch = str.charAt(i) ;
                if(ch >= 65 && ch <=90)
                {
                    capital += 1 ;
                }
                else if(ch >= 97 && ch <= 122)
                {
                    small += 1 ;
                }
                else if(ch >= 48 && ch <= 57)
                {
                    digit += 1 ;
                }
                else if(ch == '!' || ch == '@' || ch == '#' || ch == '$' || ch == '%' || ch == '^' || ch == '&' || ch == '*' || ch == '(' || ch == ')' || ch == '-' || ch == '+')
                {
                    special += 1 ;
                }
            }
            if(capital == 0)
            {
                c += 1 ;
            }
             if(small == 0)
            {
                c += 1 ;
            }
             if(digit == 0)
            {
                c += 1 ;
            }
             if(special == 0)
            {
                c += 1 ;
            }
             if(capital == 0 && small == 0 && digit == 0 && special == 0)
            {
                c = (n - 2) ;
            }
            else
             {
                 while((n + c) < 6)
                 {
                     c = c + 1 ;
                 }
             }
            System.out.println(c) ;
        }
        catch(Exception e)
        {
            return ;
        }
    }
}