#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 ans;
   ans=0;
    int count1=0;
    int count2=0;
    int count3=0;
    int count4=0;
    
  string  numbers = "0123456789";
string lower_case = "abcdefghijklmnopqrstuvwxyz";
string upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
string special_characters = "!@#$%^&*()-+";
      
      for(int i=0;i<n;i++)
      {
          for(int j=0;j<10;j++)
              if(password[i]==numbers[j])
                  count1++;
          for(int j=0;j<26;j++)
              if(password[i]==lower_case[j])
                  count2++;
          for(int j=0;j<26;j++)
              if(password[i]==upper_case[j])
                  count3++;
          for(int j=0;j<12;j++)
               if(password[i]==special_characters[j])
                   count4++;
          }
    if(count1==0)
        ans+=1;
    if(count2==0)
        ans+=1;
    if(count3==0)
        ans+=1;
    if(count4==0)
        ans+=1;
    if(ans+n<6)
        ans+=6-ans-n;
    return ans;
    
    
}

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