using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Solution {

	static int minimumNumber(int n, string password) {
		int[] lol = new int[4];
		string check = "!@#$%^&*()-+";
		int change = 0;
		int length = n;
		for (int i = 0; i<n; i++) {
			if (Char.IsDigit(password[i])&&lol[0]==0)
				lol[0]++;
			if (Char.IsLower(password[i])&&lol[1]==0)
				lol[1]++;
			if (Char.IsUpper(password[i])&&lol[2]==0)
				lol[2]++;
			if (check.Contains(password[i])&&lol[3]==0)
				lol[3]++;
		}
		for (int i = 0; i<4; i++)
			if (lol[i]==0) {
				length++;
				change++;
			}
		if (length<6)
			change+=6-length;
		return change;
	}

	static void Main(String[] args) {
		int n = Convert.ToInt32(Console.ReadLine());
		string password = Console.ReadLine();
		int answer = minimumNumber(n, password);
		Console.WriteLine(answer);

	}
}