#include<iostream>
using namespace std;
class fullexception{};
int main{
    int availableslots,students;
    cin>>availableslots;
    cin>>students;
    if(availableslots<0||students<0){
        cout<<"Invalid input";
        return 0;
    }
    try{
        if(student>availableslots){
            throw fullexception();
        }
        cout<<"Enrollment successful";
    }
    catch(fullexception){
        cout<<"Error: Insufficient slots";
    }
    return 0;
}