#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 req=4;
    for(int i=0; i<n; i++)
        if(password[i]>='a'&& password[i]<='z')
        {--req; break;}
    for(int i=0; i<n; i++)
        if(password[i]>='A'&& password[i]<='Z')
        {--req; break;}
    for(int i=0; i<n; i++)
        if(password[i]>='0'&& password[i]<='9')
        {--req; break;}
    string special = "!@#$%^&*()-+";
    
    for(int i=0; i<n; i++){
        for(int j=0; j<12; j++)
            if(special[j]==password[i]){
                i=n; --req; break;
            }
    }
   // cout<<"req ="<<req<<endl;
    if(n>=6){
        return req;
    }
    else{
        if(req+n>=6)
            return req;
        else{
            if(req<(6-n))
                return 6-n;
            else
                return req;
        }
    }
}

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