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 count = 0;
       
        String numbers = "0123456789";
        String lower_case = "abcdefghijklmnopqrstuvwxyz";
       	String upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        String special_characters = "!@#$%^&*()-+";
        
        if(!check(numbers, password))
        	count ++;
        if(!check(lower_case, password))
        	count ++;
        if(!check(upper_case, password))
        	count ++;
        if(!check(special_characters, password))
        	count ++;
        
        if(n + count < 6)
        	count += (6 - n - count);
        
        return count;
        
    }
	
	static boolean check(String s, String password) {
		for(char c : s.toCharArray()) {
        	if(password.indexOf(c) >= 0) {
        		return true;
        	}
        }
		return false;
	}

	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();
	}
}