#include <bits/stdc++.h>
using namespace std;

#define inrep for(int tc=1; tc<=t; tc++)

inline int lcm(int a, int b) {return a/__gcd(a, b)*b;}
const int N = 1e5+7;

string numbers = "0123456789", lower_case = "abcdefghijklmnopqrstuvwxyz", upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ", special_characters = "!@#$%^&*()-+";

int main()
{
	int n; cin >> n;
	string s; cin >> s;
	bool a = 0, b = 0, c = 0, d = 0;
	for(int i=0; i<s.length(); i++) {
		if (numbers.find(s[i]) != -1) {
			a = 1;
		}
		if (lower_case.find(s[i]) != -1) {
			b = 1;
		}
		if (upper_case.find(s[i]) != -1) {
			c = 1;
		}
		if (special_characters.find(s[i]) != -1) {
			d = 1;
		}
	}
	int sum = !a+!b+!c+!d;
	if (sum + s.length() >= 6) {
		cout << sum << "\n";
	}
	else {
		cout << sum + (6 - (sum+s.length())) << "\n";
	}
}