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
        Scanner sc = new Scanner(System.in);
        double time = sc.nextDouble();

        if((int)(time % 5) == 3){
            System.out.println("yellow");
        }else if((int)(time %5) == 4){
            System.out.println("red");
        }else {
            System.out.println("green");
        }

    }
}