#include <bits/stdc++.h>

using namespace std;


int main() {
    int n;
    cin >> n;
    string password;
    cin >> password;
    string numbers = "0123456789",
lower_case = "abcdefghijklmnopqrstuvwxyz",
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ",
special_characters = "!@#$%^&*()-+";
    int koliko_fali = 4;
    bool b = true;
    for(int i = 0; i < password.size() && b; i++){
        for(int j = 0; j < numbers.size(); j++){
            if(numbers[j] == password[i]){
                koliko_fali--;
                b = false;
                break;
            }
        }
    }
    b = true;
    for(int i = 0; i < password.size() && b; i++){
        for(int j = 0; j < lower_case.size(); j++){
            if(lower_case[j] == password[i]){
                koliko_fali--;
                b = false;
                break;
            }
        }
    }
    b = true;
    for(int i = 0; i < password.size() && b; i++){
        for(int j = 0; j < upper_case.size(); j++){
            if(upper_case[j] == password[i]){
                koliko_fali--;
                b = false;
                break;
            }
        }
    }
    b = true;
    for(int i = 0; i < password.size() && b; i++){
        for(int j = 0; j < special_characters.size(); j++){
            if(special_characters[j] == password[i]){
                koliko_fali--;
                b = false;
                break;
            }
        }
    }
    
    int answer = password.size();
    cout << max(koliko_fali,6-answer) << endl;
    return 0;
}