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) {
        String numbers = "0123456789";
        String lower_case = "abcdefghijklmnopqrstuvwxyz";
        String upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        String special_characters = "!@#$%^&*()-+";
        int number = 0;
        
        if(!containsChar(password,numbers)){
            number++;
        }
        if(!containsChar(password,lower_case)){
            number++;
        }
        if(!containsChar(password,upper_case)){
            number++;
        }
        if(!containsChar(password,special_characters)){
            number++;
        }
        
        if((number + n) >= 6){
            return number;
        }else{
            return (6 - (number + n)) + number;
        }        
    }
    
    static boolean containsChar(String str, String sequence){
        for(int i = 0; i < sequence.length(); i++){
            if(str.indexOf(sequence.charAt(i)) != -1){
                return true;
            } 
        }
        return false;
    }

    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();
    }
}