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
        boolean b_D=containsDigit(password);
        boolean b_U=containsUpper(password);
        boolean b_L=containsLower(password);
        boolean b_S=containsSpecial(password);
        
        int b=0;
        if(!b_D){
            b++;
        }
        if(!b_U){
            b++;
        }
        if(!b_L){
            b++;
        }
        if(!b_S){
            b++;
        }
        
        if(n+b < 6){
            return 6-n;
        }
        
        return b;
    }
    
    public static boolean containsDigit(String password){
        for(int i=0;i<password.length();i++){
            for(int j=0;j<10;j++){
                if(password.charAt(i)==(char)(j+'0')){
                    return true;
                }
            }
        }
        return false;
    }
    public static boolean containsUpper(String password){
        for(int i=0;i<password.length();i++){
            for(int j=0;j<26;j++){
                if(password.charAt(i)==(char)(j+'A')){
                    return true;
                }
            }
        }
        return false;
    }
    public static boolean containsLower(String password){
        for(int i=0;i<password.length();i++){
            for(int j=0;j<26;j++){
                if(password.charAt(i)==(char)(j+'a')){
                    return true;
                }
            }
        }
        return false;
    }
    public static boolean containsSpecial(String password){
        String s="!@#$%^&*()-+";
        for(int i=0;i<password.length();i++){
            for(int j=0;j<s.length();j++){
                if(password.charAt(i)==s.charAt(j)){
                    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();
    }
}