#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    int len = password.size();
    bool contains_digit = false;
    bool contains_lowercase = false;
    bool contains_uppercase = false;
    bool contains_special_char = false;
    
    char special_chars[] = {
        '!','@','#','$','%','^','&','*','(',')','-','+'
    };
    
    for(char c : password){
        if(c>='0' && c<='9'){
            contains_digit = true;
        }else if(c>='a'&&c<='z'){
            contains_lowercase = true;
        }else if(c>='A'&&c<='Z'){
            contains_uppercase = true;
        }else{
            for(char sc : special_chars){
                if(sc == c){
                    contains_special_char = true;
                }
            }
        }
    }
    
    int ans = 0;
    if(len < 6){
        ans = 6 - len;
    }
    ans = max(ans, !contains_digit + !contains_lowercase + !contains_uppercase + !contains_special_char);
    return ans;
}

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