#include <iostream>
using namespace std;

int main() {
   int highwayNumber;

   cin >> highwayNumber;


if (highwayNumber == 0){

 cout << highwayNumber << " is not a valid interstate highway number." << endl;

}

else if (highwayNumber >= 100){

   cout << "I-" << highwayNumber << " is auxiliary, serving I-" << highwayNumber % 100   << ", going north/south." << endl;

}


else if (highwayNumber <= 99){

  cout << "I-" << highwayNumber << " is primary, going north/south." << endl;

}

else if (highwayNumber == 0){

   cout << "I-" << highwayNumber << " is primary, going north/south." << endl;

}

else{

   cout << highwayNumber << " is not a valid interstate highway number." << endl;


}



   return 0;
}