#include <bits/stdc++.h>
using namespace std;
string s;
int n;
bool digit, lower, upper, special;
char c[] = "!@#$%^&*()-+";
int main() {
	cin >> n;
	cin >> s;
	for (int i = 0; i < n; i++) {
		if ('0' <= s[i] && s[i] <= '9') {
			digit = true;
		}
		if ('a' <= s[i] && s[i] <= 'z') {
			lower = true;
		}
		if ('A' <= s[i] && s[i] <= 'Z') {
			upper = true;
		}
		for (int j = 0; j < 12; j++) {
			if (c[j] == s[i]) {
				special = true;
			}
		}
	}
	int ans = max(6 - n, !digit + !lower + !upper + !special);
	printf("%d\n", ans);
	return 0;
}