#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
	bool hasDigit = false;
	bool hasUpper = false;
	bool hasLower = false;
	bool hasSpecial = false;
	static string special_characters = "!@#$%^&*()-+";
	for ( int i = 0; i < n; ++i ) {
		if ( !hasDigit && 
			( password[ i ] >= '0' && password[ i ] <= '9' ) ) {
			hasDigit = true;
		}
		if ( !hasLower &&
			( password[ i ] >= 'a' && password[ i ] <= 'z' ) ) {
			hasLower = true;
		}
		if ( !hasUpper && 
			( password[ i ] >= 'A' && password[ i ] <= 'Z' ) ) {
			hasUpper = true;
		}
		if ( !hasSpecial ) {
			for ( size_t j = 0; j < special_characters.size(); ++j ) {
				if ( password[ i ] == special_characters[ j ] ) {
					hasSpecial = true;
					break;
				}
			}
		}
	}
	int missing = 0;
	if ( !hasDigit ) {
		missing++;
	}
	if ( !hasLower ) {
		missing++;
	}
	if ( !hasUpper ) {
		missing++;
	}
	if ( !hasSpecial ) {
		missing++;
	}
	if ( n + missing < 6 ) {
		missing = 6-n;
	}
	return missing;
}

int main() {
    int n;
    cin >> n;
    string password;
    cin >> password;
    int answer = minimumNumber(n, password);
    cout << answer << endl;
    return 0;
}