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
        boolean special = Pattern.matches(".*[!@#$%^&*()\\-+].*",password);
        boolean upper = Pattern.matches(".*[A-Z].*", password);
        boolean lower = Pattern.matches(".*[a-z].*", password);
        boolean digit = Pattern.matches(".*[0-9].*", password);
       
        int add = 0;
        if(!special){
            add++;
        }
        if(!upper){
            add++;
        }
        if(!lower){
            add++;
        }
        if(!digit){
            add++;
        }
        
        add = n+add >= 6 ? add : 6-n;
        return add;
    }

    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();
    }
}