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
        int lower= 1, upper =1,num = 1,sym = 1;
        for(int i = 0; i < password.length();i++){
            char c = password.charAt(i);
            if( c >= 'a' && c <= 'z')lower=0;
            if( c >= 'A' && c <= 'Z')upper=0;
            if( c >= '0' && c <= '9')num=0;
            if( c == '!' || c=='@' || c == '#' || c == '$' || c =='%' || c == '^' || c == '&' || c == '*' || c== '(' || c == ')' || c =='-' || c== '+') sym = 0;
        }
        int add = upper + lower+ num +sym;
        return password.length() + add < 6 ? 6 - password.length() : add;
    }

    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();
    }
}