#include<iostream>
#include<exception>
using namespace std;
class ClassFullException:public exception
{
    public:
    const char* what() const throw()
    {
        return "Error: Insufficient Slots";
    }
};
int main()
{
    int availableSlots, studentsEnrolling;
    if(!(cin>>availableSlots>>studentsEnrolling))
    {
        return 0;
    }
    if(availableSlots<0||studentsEnrolling<0)
    {
        cout<<"Invalid input"<<endl;
        return 0;
    }
    try
    {
        if(studnetsEnrolling<=availableSlots)
        {
            cout<<"Enrolling successful"<<endl;
        }
        else
        {
            throw ClassFullException();
        }
    }
    catch(const ClassFullExceptional& e)
    {
        cout<<e.what()<<endl;
    }
    return 0;
}