#include<bits/stdc++.h>
using namespace std;
int main(){ //
	int n;
	cin>>n;
	if(n==1) cout<<"pen";
	else if(n==2) cout<<"pencil";
	else if(n==3) cout<<"eraser";
	else if(n==4) cout<<"ruler";
	else if(n==5) cout<<"notebook";
	else cout<<"error";
    return 0;
}