import java.util.*;
import java.lang.*;
import java.io.*;

import java.util.Calendar;
import java.util.HashMap;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone {
	
	private static int secondsAgo;

	private static HashMap<Integer, Long> cooldown = new HashMap<Integer, Long>();
	
	public Ideone() {
		secondsAgo = 30;
	}
	
	public static void main (String[] args) throws java.lang.Exception {
		
		for ( int c=0; c<5; c++ ) {
			for ( int i=0; i<5; i++ ) {
				
				if (cooldown(i)) {
					System.out.println("ID "+i+" passed!");
				} else {
					System.out.println("ID "+i+" waiting for cooldown!");
				}
				
			}
		}
		
	}
	
	public static Boolean cooldown(int id) {

		Calendar now = Calendar.getInstance();
		now.add(Calendar.SECOND, -secondsAgo);
		long timeAgo = now.getTimeInMillis();
	    if ( cooldown.containsKey(id) ) {
				
			System.out.println(cooldown.get(id) + " | " + timeAgo);
				
            // Stored timestamp always older than timeAgo
			if ( cooldown.get(id) < timeAgo ) {
					
				cooldown.remove(id);
					
			} else {
					
                return false;
					
			}

    	}
    	
	    now = Calendar.getInstance();
	    cooldown.put(id, now.getTimeInMillis());
    	
    	return true;
	
    }
	
}