#include <bits/stdc++.h>

using namespace std;

int add(string s1, string s2) {
    for (int i = 0; i < s1.length(); i++) {
        for (int j = 0; j < s2.length(); j++) {
            if (s2[j] == s1[i]) {
                return 0;
            }
        }
    }
    return 1;
}

int minimumNumber(int n, string s) {
    string num = "0123456789";
    string lc = "abcdefghijklmnopqrstuvwxyz";
    string uc = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string spec = "!@#$%^&*()-+";
    int need = add(s, num) + add(s, lc) + add(s, uc) + add(s, spec);
    return max(6-n, need);
}

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