#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";
    int nums = 0;
    int locases = 0;
    int upcases = 0;
    string special_characters = "!@#$%^&*()-+";
    int spec = 0;
    int remain = 0;
    for(int i = 0; i < password.length(); ++i) {
        if(numbers.find(password[i]) != string::npos) ++nums;
        if(lower_case.find(password[i]) != string::npos) ++locases;
        if(upper_case.find(password[i]) != string::npos) ++upcases;
        if(special_characters.find(password[i]) != string::npos) ++spec;
    }
    if(nums == 0) ++remain;
    if(locases == 0) ++remain;
    if(upcases == 0) ++remain;
    if(spec == 0) ++remain;
    if(password.length() < 4) {
        remain = 6 - password.length();
        return remain;
    }
    if(password.length() < 6) {
        if(nums && locases && upcases && spec) {
            remain = 6 - password.length();
            return remain;
        }
        else if(6 - password.length() >= remain){
            remain = 6 - password.length();
            return remain;
        }
        else return remain;
    }
    else {
        return remain;
    }
}

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