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 min = 0, pwdLength = password.length();
        
        if (!password.matches(".*[0123456789]+.*")) {
            min++;
            pwdLength++;
        }
        
        if (!password.matches(".*[abcdefghijklmnopqrstuvwxyz]+.*")) {
            min++;
            pwdLength++;
        }
        
        if (!password.matches(".*[ABCDEFGHIJKLMNOPQRSTUVWXYZ]+.*")) {
            min++;
            pwdLength++;
        }
        
        if (!password.matches(".*[\\!@#\\$%\\^&\\*\\(\\)\\-\\+]+.*")) {
            min++;
            pwdLength++;
        }
        
        if (pwdLength < 6) {
            min = min + 6 - pwdLength;
        }
        
        return min;
    }

    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();
    }
}