package com.codegym.task.task04.task0416;
/*
Crossing the road blindly
*/
import java.io.*;
import java.util.Scanner;
public class Solution {
public static void main(String[] args) throws Exception {
//write your code here
//BuffererdReader br=new BuffererdReader(new InputStreamReder(System.in));
// double num=double.parseDouble(br.readLine());
Scanner sc=new Scanner(System.in);
double num=sc.nextDouble();
double n=num%5;
if((n>=0.10) && (n<3)){
System.out.println("green");}
else if((n>=3.00) && (n<4 )){
System.out.println("yellow");}
else if((n>=4.00) && (n<5)){
System.out.println("red");}
num=num/5;
}
}