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) {
        String numbers = "0123456789";
        String lower_case = "abcdefghijklmnopqrstuvwxyz";
        String upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        String special_characters = "!@#$%^&*()-+";
        
        boolean hasDigit = false;
        boolean hasSpecial = false;
        boolean hasUpper = false;
        boolean hasLower = false; 
        for(char ch : password.toCharArray()) {
            if(Character.isUpperCase(ch))
                hasUpper = true;
            if(Character.isLowerCase(ch))
                hasLower = true;
            if(Character.isDigit(ch))
                hasDigit = true;
            for(int i = 0; i < special_characters.length(); i++) {
                if(ch == special_characters.charAt(i)) {
                    hasSpecial = true;
                }
            }
         }
         int count = 0;
         if(!hasDigit)
             count++;
         if(!hasUpper)
             count++;
        if(!hasLower)
             count++;
        if(!hasSpecial)
             count++;
        if(count + n < 6)
            count += 6 - (n + count); 
        return count;
    }

    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();
    }
}