#include <bits/stdc++.h>

using namespace std;

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

int minimumNumber(int n, string password) {
    bool num = true, low = true, upp = true, spec = true;
    for (char c : password) {
        if (numbers.find(c) != string::npos)
            num = false;
        if (lower_case.find(c) != string::npos)
            low = false;
        if (upper_case.find(c) != string::npos)
            upp = false;
        if (special_characters.find(c) != string::npos)
            spec = false;
    }
    int ss = num + low + upp + spec;
    return max(max(0, 6-n),ss);
}

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