import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    static int minimumNumber(int n, String password) {
        // Return the minimum number of characters to make the password strong
                
        String numbers = "0123456789";
        String lower_case = "abcdefghijklmnopqrstuvwxyz";
        String upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        String special_characters = "!@#$%^&*()-+";
        
        int cnt = 0;
        boolean contains = false;
        for (int i = 0; i < numbers.length();i++){
            if(password.contains(numbers.charAt(i)+"")){
                contains = true;
                break;
            }            
        }               
        if(!contains)
           cnt++;
               
        contains = false;
        for (int i = 0; i < lower_case.length();i++){
            if(password.contains(lower_case.charAt(i)+"")){
                contains = true;         
                break;
            }            
        }       
        if(!contains)
           cnt++;
               
        contains = false;
        for (int i = 0; i < upper_case.length();i++){
            if(password.contains(upper_case.charAt(i)+"")){
                contains = true;    
                break;
            }            
        }               
        if(!contains)
           cnt++;
               
        contains = false;
        for (int i = 0; i < special_characters.length();i++){
            if(password.contains(special_characters.charAt(i)+"")){
                contains = true;      
                break;
            }            
        }                    
        if(!contains)
           cnt++;
        
        if(password.length()+cnt<6){            
            cnt += (6 - password.length() - cnt);
        }
               
        return cnt;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        String password = in.next();
        int answer = minimumNumber(n, password);
        System.out.println(answer);
        in.close();
    }
}