import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class StrongPassword {

    static int minimumNumber(int n, String password) {
        // Return the minimum number of characters to make the password strong
    	String numbers = "0123456789";
    	String lowerCase = "abcdefghijklmnopqrstuvwxyz";
    	String upperCase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    	String specialCharacters = "!@#$%^&*()-+";
    	
    	Set<String> passwordSet = new HashSet<>();
    	for(int i=0; i<password.length(); i++){
    		passwordSet.add(password.charAt(i)+"");
    	}
    	
    	Set<String> numbersSet = new HashSet<>();
    	for(int i=0; i<numbers.length(); i++){
    		numbersSet.add(numbers.charAt(i)+"");
    	}
    	
    	Set<String> lowerCaseSet = new HashSet<>();
    	for(int i=0; i<lowerCase.length(); i++){
    		lowerCaseSet.add(lowerCase.charAt(i)+"");
    	}
    	//check if lowerCase is present
    	lowerCaseSet.retainAll(passwordSet);
    	boolean hasLowerCase = !lowerCaseSet.isEmpty();
    	
    	Set<String> upperCaseSet = new HashSet<>();
    	for(int i=0; i<upperCase.length(); i++){
    		upperCaseSet.add(upperCase.charAt(i)+"");
    	}
    	//check if upperCase is present
    	upperCaseSet.retainAll(passwordSet);
    	boolean hasUpperCase = !upperCaseSet.isEmpty();
    	
    	Set<String> specialCharacterSet = new HashSet<>();
    	for(int i=0; i<specialCharacters.length(); i++){
    		specialCharacterSet.add(specialCharacters.charAt(i)+"");
    	}
    	//check if special character is present
    	specialCharacterSet.retainAll(passwordSet);
    	boolean hasSpecialCharacter = !specialCharacterSet.isEmpty();
    	
    	//check if a number is present
    	numbersSet.retainAll(passwordSet);
    	boolean hasNumber = !numbersSet.isEmpty();
    	
    	int no = 0;
    	if(!hasUpperCase){
//    		System.out.println("Has no upper case");
    		no++;
    	}
    	if(!hasLowerCase){
//    		System.out.println("Has no lower case");
    		no++;
    	}
    	if(!hasSpecialCharacter){
//    		System.out.println("Has no special character");
    		no++;
    	}
    	if(!hasNumber){
//    		System.out.println("Has no number");
    		no++;
    	}
    	
    	int newLength = password.length() + no;
    	
    	
    	if(newLength < 6){
//    		no = 6 - password.length();
    		no = 6-newLength + no;
    	}
    	
//    	for(String s: passwordSet){
//    		System.out.print(s);
//    	}
    	return no;
    }

    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();
    }
}