#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
    int i =0;
    std::string specialChars = "!@#$%^&*()-+";
    int digit=1, upper=1, lower =1, special =1;
    int length = password.length();
    char curr;
    while(password[i]!=0){
        curr = password[i];
        if(curr>='0' && curr<='9'){
            digit =0; 
        }
        else if (curr>='a' && curr<='z'){
            lower = 0;
        }
        else if (curr>='A' && curr<='Z'){
            upper = 0;
        }else if (specialChars.find(curr)!=std::string::npos){
            special =0;
        }
        
        if(digit==1 && upper==1 && lower ==1 && special ==1 && length >=6){
            return 0;  
        }
        i++;
    }
    
    if(length >= 6){
        return digit+upper+lower+special;
    }else{
        if(length<=2){
            return 6-length;
        }else if(digit+upper+lower+special>6-length){
            return digit+upper+lower+special;
        }
        else{
            return 6-length;
        }
        
    }
    
}

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