#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
    string numbers = "0123456789";
    string lower_case = "abcdefghijklmnopqrstuvwxyz";
    string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string special_characters = "!@#$%^&*()-+";
    int numbersFlag = 0;
    int lcFlag = 0;
    int upFlag = 0;
    int specFlag = 0;
    
    if (password.size() < 3) return (6 - password.size());
    for (int i = 0; i < password.size(); i++) {
        if (numbersFlag == 0 && numbers.find(password[i])!=std::string::npos) { numbersFlag = 1;}
        if (lcFlag == 0 && lower_case.find(password[i])!=std::string::npos) { lcFlag = 1; }
        if (upFlag == 0 && upper_case.find(password[i])!=std::string::npos) { upFlag = 1; }
        if (specFlag == 0 && special_characters.find(password[i])!=std::string::npos) { specFlag = 1; }
    }
    int count = 4 - (numbersFlag + lcFlag + upFlag + specFlag);
    if (password.size() + count < 6) return (6 - password.size());
    else return count;
}

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