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 str) {
        // Return the minimum number of characters to make the password strong
        boolean[] a=new boolean[4];
        String s="!@#$%^&*()-+";
        char[] sp=s.toCharArray();
        for(int i=0;i<n;i++){
            if(str.charAt(i)>=48 && str.charAt(i)<=57)
                a[0]=true;
            else if(str.charAt(i)>=97 && str.charAt(i)<=122)
                a[1]=true;
            else if(str.charAt(i)>=65 && str.charAt(i)<=90)
                a[2]=true;
            else{
                for(int j=0;j<12;j++){
                if(str.charAt(i)==sp[j])
                    a[3]=true;
                }
            }
        }
        int count=0;
        for(int i=0;i<4;i++){
            if(!a[i]) count++;
        }
        int len=str.length();
        len+=count;
        if(len<6)
            count+=(6-len);
        return count;
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();in.nextLine();
        String password = in.nextLine();
        int answer = minimumNumber(n, password);
        System.out.println(answer);
        in.close();
    }
}