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 num = 4;
        for (char c : "0123456789".toCharArray()){
            if (password.indexOf(c) != -1){
                num -= 1;
                break;
            }
        }
        for (char c : "abcdefghijklmnopqrstuvwxyz".toCharArray()){
            if (password.indexOf(c) != -1){
                num -= 1;
                break;
            }
        }
        for (char c : "ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray()){
            if (password.indexOf(c) != -1){
                num -= 1;
                break;
            }
        }
        for (char c : "!@#$%^&*()-+".toCharArray()){
            if (password.indexOf(c) != -1){
                num -= 1;
                break;
            }
        }
        
        if (n + num < 6) { num += 6-(n+num); }
        return num;
    }

    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();
    }
}