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

public class Solution {

    public static void main(String[] args)
    {
        Scanner in = new Scanner(System.in);

        int n = in.nextInt();
        String s = in.next();

        int checks = 0;

        if (s.matches(".*[0-9]+.*"))
            checks++;
        if (s.matches(".*[a-z]+.*"))
            checks++;
        if (s.matches(".*[A-Z]+.*"))
            checks++;
        if (s.matches(".*[\\!\\@\\#\\$\\%\\^\\&\\*\\(\\)\\-\\+]+.*"))
            checks++;

        System.out.println(Math.max(6 - n, 4 - checks));

        in.close();
    }
}