#include <bits/stdc++.h>

using namespace std;

bool appears(char c) {
    string s = "!@#$%^&*()-+";
    for (auto it : s) if (it == c) return true;
    return false;
}

int minimumNumber(int n, string password) {
    bool dig = false;
    bool lc = false;
    bool uc = false;
    bool sc = false;
    for (int i = 0; i < n; ++i) {
        if (isdigit(password[i])) dig = true;
        if (password[i] >= 'a' && password[i] <= 'z') lc = true;
        if (password[i] >= 'A' && password[i] <= 'Z') uc = true;
        if (appears(password[i])) sc = true;
    }
    int add = 0;
    add += !dig;
    add += !lc;
    add += !uc;
    add += !sc;
    add += max(0, 6 - n - add);
    return add;
}

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