#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
string numbers = "0123456789";
string lower_case = "abcdefghijklmnopqrstuvwxyz";
string  upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string special_characters = "!@#$%^&*()-+";

bool hasElem(string s, string ref) {
	for (auto it = s.begin(); it != s.end(); ++it)
		if (ref.find(*it) != string::npos)
			return true;
	return false;
}

int forGoodPwd(int n, string pwd) {
	int req = 0;
	if (!hasElem(pwd, numbers)) req += 1;
	if (!hasElem(pwd, lower_case)) req += 1;
	if (!hasElem(pwd, upper_case)) req += 1;
	if (!hasElem(pwd, special_characters)) req += 1;
	return (max(n + req, 6) - n);
}

int main() {
	int len;
	string pwd;
	cin >> len >> pwd;
	int n = forGoodPwd(len, pwd);
	cout << n << endl;
	return 0;
}