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) {
        boolean hasDigit = false;
        boolean hasLower = false;
        boolean hasUpper = false;
        boolean hasSpecial = false;
        Set<Character> special = new HashSet<>();
        String spe = "!@#$%^&*()-+";
        for(int i =0; i<spe.length(); i++){
            special.add(spe.charAt(i));
        }
        for(int i =0; i<password.length(); i++){
            char c = password.charAt(i);
            if(c>='0'&&c<='9'){
                hasDigit=true;
            }
            if(c>='a'&&c<='z'){
                hasLower = true;
            }
            if(c>='A'&&c<='Z'){
                hasUpper=true;
            }
            if(special.contains(c)){
                hasSpecial= true;;
            }
        }
        if(!hasDigit){
            n++;
        }
        if(!hasLower){
            n++;
        }if(!hasUpper){
            n++;
        }if(!hasSpecial){
            n++;
        }
        if(n<6){
            n=6;
        }
        return n-password.length();
    }

    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();
    }
}