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

public class Solution {

    
    static boolean hasSpecialChar(String password) {
        Set<String> specialCharSet = new HashSet<String>();
        specialCharSet.add("!");
        specialCharSet.add("@");
        specialCharSet.add("#");
        specialCharSet.add("$");
        specialCharSet.add("%");
        specialCharSet.add("^");
        specialCharSet.add("&");
        specialCharSet.add("*");
        specialCharSet.add("(");
        specialCharSet.add(")");
        specialCharSet.add("-");
        specialCharSet.add("+");
        boolean flag = false;
        for(String s : specialCharSet) {
            flag = flag | password.contains(s);
        }
        return flag;
    }
    
    static boolean hasOneLowerCaseChar(String password) {
        boolean flag = false;
        for(Character c : password.toCharArray()) {
            flag = flag | Character.isLowerCase(c);
        }
        return flag;
    }
    
    static boolean hasOneUpperCaseChar(String password) {
        boolean flag = false;
        for(Character c : password.toCharArray()) {
            flag = flag | Character.isUpperCase(c);
        }
        return flag;
    }
    
    static boolean hasDigit(String password) {
        boolean flag = false;
        for(Character c : password.toCharArray()) {
            flag = flag | Character.isDigit(c);
        }
        return flag;
    }
    static int minimumNumber(int n, String password) {
        
        int i=0;
        if (!hasDigit(password)) i++;
        if (!hasOneUpperCaseChar(password)) i++;
        if (!hasOneLowerCaseChar(password)) i++;
        if (!hasSpecialChar(password)) i++;
        
        int length = password.length();
        int result = 0;
        if(length < 6) {
            if(6-length <= i) {
                result = i;
            } else  {
                result = 6-length;
            } 
        } else {
            result = i;
        }
        return result;
        // 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();
    }
}