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

import java.util.*;

public class Solution {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int T = in.nextInt(); //test cases
		String str = in.next();
		char[] numbers = "0123456789".toCharArray();
		char[] lower_case = "abcdefghijklmnopqrstuvwxyz".toCharArray();
		char[] upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
		char[] special_characters = "!@#$%^&*()-+".toCharArray();
		in.close();
		int count = 0;
		boolean[] trues = new boolean[4];
		for (int j = 0; j < numbers.length; j++) {
			if (str.indexOf(numbers[j]) >= 0) {
				trues[0] = true;
				break;
			}
		}
		for (int j = 0; j < lower_case.length; j++) {
			if (str.indexOf(lower_case[j]) >= 0) {
				trues[1] = true;
				break;
			}
		}
		for (int j = 0; j < upper_case.length; j++) {
			if (str.indexOf(upper_case[j]) >= 0) {
				trues[2] = true;
				break;
			}
		}
		for (int j = 0; j < special_characters.length; j++) {
			if (str.indexOf(special_characters[j]) >= 0) {
				trues[3] = true;
				break;
			}
		}
		for (int i = 0; i < 4; i++) {
			if (!trues[i]) count++;
		}
		if (T + count < 6) {
			System.out.println(6 - T);
			
		}else System.out.println(count);
	}
	
//	public int function(int[] arr) {
//		
//	}
}