#include <bits/stdc++.h>

using namespace std;

string numbers = "0123456789";
string lower_case = "abcdefghijklmnopqrstuvwxyz";
string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string special_characters = "!@#$%^&*()-+";

bool findChar(char c, string cad){
    for(int i=0;i<cad.length();i++){
        if(cad[i]==c)
            return true;
    }
    return false;
}

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
    bool number=false;
    bool lower=false;
    bool upper=false;
    bool special=false;
    bool len=false;
    
    for(int i=0;i<n;i++){
        if(!number)
            number = findChar(password[i], numbers);
        if(!lower)
            lower = findChar(password[i], lower_case);
        if(!upper)
            upper = findChar(password[i], upper_case);
        if(!special)
            special = findChar(password[i], special_characters);
        
        if(number && lower && upper && special) break;
    }
    
    if(n >= 6) len = true;
    
    int result = 0;
    
    if(!number) result++;
    if(!lower) result++;
    if(!upper) result++;
    if(!special) result++;
    
    result += 6 - n - result > 0 ? 6 - n - result : 0;
    return result;
}

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