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

public class Solution {

    private static Set<Character> spcl;

    static int minimumNumber(int n, String password) {
        boolean len = false, dig = false, lc = false, uc = false, sc = false;
        int toAdd = 0;
        // Return the minimum number of characters to make the password strong
        for (int i = 0; i < n; i++) {
            char ch = password.charAt(i);
            if (Character.isDigit(ch)) {
                dig = true;
            } else if (Character.isLowerCase(ch)) {
                lc = true;
            } else if (Character.isUpperCase(ch)) {
                uc = true;
            } else if (spcl.contains(ch)) {
                sc = true;
            }
        }
        
        if (!dig) {
            toAdd += 1; 
        }
        if (!lc) {
            toAdd += 1;
        }
        if (!uc) {
            toAdd += 1;
        }
        if (!sc) {
            toAdd += 1;
        }
        int newLen = n + toAdd;
        if (newLen < 6) {
            toAdd += 6 - newLen;
        }
        
        return toAdd;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        String password = in.next();
        spcl = new HashSet<Character>(Arrays.asList('!', '@', '#', '$', '%', '^', '&', '*', '(', ')', '-', '+'));
        int answer = minimumNumber(n, password);
        System.out.println(answer);
        in.close();
    }
}