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 cnt=0;
        int len=password.length();
        int dig=0;
        int lower=0;
        int upper=0;
        int special=0;
        String st="!@#$%^&*()-+";
        Set<Character> myset=new HashSet<>();
        for(int i=0;i<st.length();i++){
            char c=st.charAt(i);
            myset.add(c);
        }
        for(int i=0;i<password.length();i++){
            char c=password.charAt(i);
            if(myset.contains(c))
                special++;
            if(c>=48 && c<=57)
                dig++;
            if(c>=65 && c<=90)
                upper++;
            if(c>=97 && c<=122)
                lower++;
        }
        if(special==0)
            cnt++;
        if(dig==0)
            cnt++;
        if(upper==0)
            cnt++;
        if(lower==0)
            cnt++;
        if(len+cnt<6)
            cnt+=6-len-cnt;
        return cnt;
        // Return the minimum number of characters to make the password strong
    }

    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();
    }
}