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) {
        // Return the minimum number of characters to make the password strong
        String s1 = "!@#$%^&*()-+";
        char[] sc = new char[12];
        for(int i=0; i<12; i++)
            sc[i] = s1.charAt(i);
        boolean d=false, u=false, l=false, s=false;
        for(int i=0; i<password.length(); i++)
        {
            char ch = password.charAt(i);
            if(ch - 'A' >=0 && ch - 'A' <= 25)
                u = true;
            else if(ch - 'a' >=0 && ch - 'a' <=25)
                l = true;
            else if(ch - '0' >=0 && ch - '0' <= 9)
                d = true;
            for(int j=0; j<12; j++)
            {
                if(ch == sc[j])
                    s = true;
            }
        }
        //System.out.println(u + " " + l + " " + d + " " + s);
            int count = password.length(), c=0;
            if(!d)
            {
                count++;
                c++;
            }
            if(!u)
            {
                count++;
                c++;
            }
            if(!l)
            {
                count++;
                c++;
            }
            if(!s)
            {
                count++;
                c++;
            }
            if(count>=6)
                return c;
            else
                return c + (6-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();
    }
}