#include <bits/stdc++.h>

using namespace std;

int minimumNumber(int n, string password) {
    // Return the minimum number of characters to make the password strong
 string numbers = "0123456789",lower_case = "abcdefghijklmnopqrstuvwxyz",upper_case ="ABCDEFGHIJKLMNOPQRSTUVWXYZ",
    special_characters = "!@#$%^&*()-+";
    int count=0, temp, nn=0, l=0, u=0, s=0;
    
    for(int i=0; i< n; i++){
        if(numbers.find(password[i])!=string::npos){
            nn++;
        }
         if(lower_case.find(password[i])!=string::npos){
            l++;
        }
         if(upper_case.find(password[i])!=string::npos){
            u++;
        }
        if(special_characters.find(password[i])!=string::npos){
            s++;
        }
    }
    
        if(nn==0)count++;
        if(l==0)count++;
        if(u==0)count++;
    if(s==0)count++;
        
   if((n+count)<6)
   {
       count+=6-(n+count);
   }
    return count;
}

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