#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    string special_characters = "!@#$%^&*()-+";
    int  haveDigit = 0 , haveLowerCase = 0 , haveUpperCase = 0 , haveSpecial = 0;
    for(int i = 0; i < password.size(); i++)
    {
        for(int j = 0; j < special_characters.size(); j++)
        {
            if(password[i] == special_characters[j])
                haveSpecial = 1;
        }
        if(password[i] >= '0' && password[i] <= '9')
            haveDigit = 1;
        
        if(password[i] >= 'a' && password[i] <= 'z')
            haveLowerCase = 1;
        
        if(password[i] >= 'A' && password[i] <= 'Z')
            haveUpperCase = 1;
    }
    return max(max(0 , 6 - (int)password.size()) , !haveSpecial + !haveDigit + !haveLowerCase + !haveUpperCase);
}

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