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