import java.util.Scanner;

public class Solution {

	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int T = in.nextInt();
		String pass = in.next();
		int diff=0;
		int upper = 0, lower=0,digit=0, special=0;
		String special_characters = "!@#$%^&*()-+";
		for(int i=0; i<pass.length(); ++i) {
			if(Character.isUpperCase(pass.charAt(i))) {
				++upper;
			}
			if(Character.isLowerCase(pass.charAt(i))) {
				++lower;
			}
			if(Character.isDigit(pass.charAt(i))) {
				++digit;
			}
		}
		for(int i=0; i<special_characters.length(); ++i) {
			for(int j=0; j<pass.length(); ++j) {
				if(special_characters.charAt(i) == pass.charAt(j)) {
					++special;
				}
			}
		}
		if(pass.length() < 6) {
			int temp = 0;
			if(upper == 0) {
				++temp;
			}
			if(lower == 0) {
				++temp;
			}
			if(special == 0) {
				++temp;
			}
			if(digit==0) {
				++temp;
			}
			

			if((temp + pass.length()) < 6) {
				temp += 6 - (pass.length() + temp);
			}
			System.out.println(temp);
			System.exit(0);
		}else {
			if(upper == 0) {
				++diff;
			}
			if(lower == 0) {
				++diff;
			}
			if(digit == 0) {
				++diff;
			}
			if(special==0) {
				++diff;
			}
			System.out.println(diff);
		}
	}
}