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

public class Solution {

    public static void main(String[] args) {
        Scanner scn = new Scanner(System.in);
		int n = scn.nextInt();
		scn.nextLine();
		String s1 = scn.nextLine();
		int count = 0;
		HashMap<Character, Boolean> map1 = new HashMap<>();
		HashMap<Character, Boolean> map2 = new HashMap<>();
		HashMap<Character, Boolean> map3 = new HashMap<>();
		HashMap<Character, Boolean> map4 = new HashMap<>();
		boolean b1 = false;
		boolean b2 = false;
		boolean b3 = false;
		boolean b4 = false;

		String s = "0123456789";
		for (int i = 0; i < s.length(); i++) {
			map1.put(s.charAt(i), false);
		}
		s = "abcdefghijklmnopqrstuvwxyz";
		for (int i = 0; i < s.length(); i++) {
			map2.put(s.charAt(i), false);
		}
		s = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
		for (int i = 0; i < s.length(); i++) {
			map3.put(s.charAt(i), false);
		}
		s = "!@#$%^&*()-+";
		for (int i = 0; i < s.length(); i++) {
			map4.put(s.charAt(i), false);
		}

		for (int i = 0; i < s1.length(); i++) {
			char ch = s1.charAt(i);
			if (map1.containsKey(ch)) {
				b1 = true;
			} else if (map2.containsKey(ch)) {
				b2 = true;
			} else if (map3.containsKey(ch)) {
				b3 = true;
			} else if (map4.containsKey(ch)) {
				b4 = true;
			}
		}

		if (!b1) {
			count++;
		}

		if (!b2) {
			count++;
		}

		if (!b3) {
			count++;
		}

		if (!b4) {
			count++;
		}
		
		if(s1.length() < 6) {
			if(s1.length() + count < 6) {
				System.out.println(6 - s1.length());
			} else {
				System.out.println(count);
			}
		} else {
			System.out.println(count);
		}
    }
}