//
//  main.cpp
//  hackerrank1
//
//  Created by Alex Mazalov on 02/11/2017.
//  Copyright © 2017 Alvis Internet Solutions Ltd. All rights reserved.
//
/*
#include <iostream>

int main(int argc, const char * argv[]) {
    // insert code here...
    std::cout << "Hello, World!\n";
    return 0;
}
*/

//#include </Users/amazalov/bits/stdc++.h>

 #include <bits/stdc++.h>
#include <string.h>
#include <math.h>
#include <algorithm>

using namespace std;

int minimumNumber(int n, string password) {
    string numbers = "0123456789";
    string lower_case = "abcdefghijklmnopqrstuvwxyz";
    string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    string special_characters = "!@#$%^&*()-+";
    
    int digit = 1;
    int lc = 1;
    int uc = 1;
    int specialC = 1;
    for (int i = 0; i < n; i++) {
        if (numbers.find(password[i]) != std::string::npos) {
            digit = 0;
        }
        if (lower_case.find(password[i]) != std::string::npos) {
            lc = 0;
        }
        if (upper_case.find(password[i]) != std::string::npos) {
            uc = 0;
        }
        if (special_characters.find(password[i]) != std::string::npos) {
            specialC = 0;
        }
    }
    return max(digit + lc + uc + specialC, (int)(6-password.length()));
    
}

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