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) {
        
        int checks = 4;
        String numbers = "0123456789";
        String lower_case = "abcdefghijklmnopqrstuvwxyz";
        String upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        String special_characters = "!@#$%^&*()-+";
        
        for(int i=0;i<numbers.length();i++) {
            if(password.indexOf(numbers.charAt(i)) > -1) {
                checks--;
                break;
            }   
        }
        for(int i=0;i<lower_case.length();i++) {
            if(password.indexOf(lower_case.charAt(i)) > -1) {
                checks--;
                break;
            }   
        }
        for(int i=0;i<upper_case.length();i++) {
            if(password.indexOf(upper_case.charAt(i)) > -1) {
                checks--;
                break;
            }   
        }
        for(int i=0;i<special_characters.length();i++) {
            if(password.indexOf(special_characters.charAt(i)) > -1) {
                checks--;
                break;
            }   
        }
        if(n >= 6) {
            return checks;
        }else if (n + checks >= 6) {
            return checks;
        }else {
            return checks + (6 - n - checks);
        }
    }

    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();
    }
}