package com.codegym.task.task04.task0416;

/*
Crossing the road blindly

*/

import java.io.*;

public class Solution {
    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        double t = Double.parseDouble(reader.readLine());

        if ((t >= 0.0 && t <= 3.0) || (t > 5.0 && t <= 8.0) || (t > 10.0 && t <= 13.0) || (t > 15.00 && t <= 18.0) || (t > 20.0 && t <= 23.0) || (t > 25.0 && t <= 28.0) || (t > 30.0 && t <= 33.0) || (t > 35.0 && t <= 38.0) || (t > 40.0 && t <= 43.0) || (t > 45.0 && t <= 48.0) || (t > 50.0 && t <= 53.0) || (t > 55.0 && t <= 58.0)) {
             System.out.println("green"); }
        else if ((t > 3.0 && t <= 4.0) || (t > 8.0 && t <= 9.0) || (t > 13.0 && t <= 14.0) || (t > 18.0 && t <= 19.0) || (t > 23.0 && t <= 24.0) || (t > 28.0 && t <= 29.0) || (t > 33.0 && t <= 34.0) || (t > 38.0 && t <= 39.0) || (t > 43.0 && t <= 44.0) || (t > 48.0 && t <= 49.0) || (t > 53.0 && t <= 54.0) || (t > 58.0 && t <= 59.0)) {
             System.out.println("yellow"); }
        else if ((t > 4.0 && t <= 5.0) || (t > 9.0 && t <= 10.0) || (t > 14.0 && t <= 15.0) || (t > 19.0 && t <= 20.0) || (t > 24.0 && t <= 25.0) || (t > 29.0 && t <= 30.0) || (t > 34.0 && t <= 35.0) || (t > 39.0 && t <= 40.0) || (t > 44.0 && t <= 45.0) || (t > 49.0 && t <= 50.0) || (t > 54.0 && t <= 55.0) || (t > 59.0 && t <= 60.0)) {
             System.out.println("red"); }

    }
}