public static void defend(PlanetWars pw) {	//send ships from the lowest growing planet to the best one
		// Tested
		int maxGR = 0;
		int minGR = 5;
		Planet source = null;
		Planet dest = null;
		for (Planet p : pw.MyPlanets()){
			int gr = p.GrowthRate();
			if (gr>maxGR){
				maxGR = gr;
				dest = p;
			}
			if (gr<minGR){
				minGR = gr;
				source = p;
			}
		}

		if (source != null && dest != null) {
			pw.IssueOrder(source, dest);
		}

		updateLearning(-1);
	}