#include <bits/stdc++.h>

using namespace std;
string arr[] = {"0123456789", "abcdefghijklmnopqrstuvwxyz", "ABCDEFGHIJKLMNOPQRSTUVWXYZ", "!@#$%^&*()-+"};
int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
    map < char, bool > M;
    for(int i = 0; i < password.size(); ++i) M[password[i]] = 1;
    int res = 0;
    for(int i = 0; i < 4; ++i) {
        bool ok = 0;
        for(int j = 0; j < arr[i].size(); j++) {
            ok |= M[arr[i][j]];
        }
        res += !ok;
    }
    return res + max(0, (int)(6 - (res + password.size())));
}

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