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 num, lc, uc, sc;
        num = lc = uc = sc = false;
        String numbers = "(.*)[0123456789]+(.*)";
        String lower_case = "(.*)[abcdefghijklmnopqrstuvwxyz]+(.*)";
        String upper_case = "(.*)[ABCDEFGHIJKLMNOPQRSTUVWXYZ]+(.*)";
        String special_characters = "(.*)[!@#\\$%\\^&\\*\\(\\)\\-\\+]+(.*)";
        
        num = Pattern.matches(numbers, password);
        uc = Pattern.matches(upper_case, password);
        lc = Pattern.matches(lower_case, password);
        sc = Pattern.matches(special_characters, password);
        
        int nu, u, l, s;
        nu = u = l = s = 0;
        if(!num)
            nu++;
        if(!uc)
            u++;
        if(!lc)
            l++;
        if(!sc)
            s++;
        int need = (nu + u + l + s);
        
        if(n >= 6){
            return need;
        }
        if(need > (6-n))
            return need;
        return (6 - n);
    }

    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();
    }
}