public static void DoTurn(PlanetWars pw) {
		// Tested
				
		//Retrieve environment characteristics
		//Are there characteristics you want to use instead, or are there more you'd like to use? Try it out!
		// int neutralPlanets = pw.NeutralPlanets().size();
		// int totalPlanetSize = 0;
		// for (Planet p : pw.NeutralPlanets()) {
		// 	totalPlanetSize += p.GrowthRate();
		// }
		// int averagePlanetSize = Math.round(totalPlanetSize/pw.NeutralPlanets().size());
		
		int planets = pw.MyPlanets().size() - pw.EnemyPlanets().size();	// myPlanets - EnemyPlanets => positive mean that I have more planets than the enemy
		int ships = Helper.shipsValue(pw);								// myShips - enemyShips
		int growth = Helper.growthValue(pw);							// myGrowth - enemyGrowth		
		int fleet = Helper.fleetValue(pw);								// The maximum fleet able to be send minus the average fleet on each planet.

		int planetsL = 0;	// L is for learn (to modify the if depending on victories or defeats)
		int shipsL = 0;
		int growthL = 0;		
		int fleetL = 0;

		try {	// Try to read values from the file
			BufferedReader reader = new BufferedReader(new FileReader("learn.txt"));
			String line = null;

			line = reader.readLine();
			planetsL = Integer.valueOf(line);
			line = reader.readLine();
			shipsL = Integer.valueOf(line);
			line = reader.readLine();
			growthL = Integer.valueOf(line);
			line = reader.readLine();
			fleetL = Integer.valueOf(line);

			PrintWriter writer = new PrintWriter("values.txt", "UTF-8");
			writer.println("Planets : " + planets);
			writer.println("Ships : " + ships);
			writer.println("Growth : " + growth);
			writer.println("Fleet : " + fleet);
			writer.close();
		}
		catch (Exception e){
			// File must not exist or being inconsistent so we create it
			try {
				PrintWriter writer = new PrintWriter("learn.txt", "UTF-8");
				writer.println(0);
				writer.println(0);
				writer.println(0);
				writer.println(0);
				writer.close();
			}
			catch (Exception ee){
				System.out.println(ee);
			}
			// Finally throw an exception : 
			System.out.println(e);
		}

		/////////////////////
		// Tree selection :
		////////////////////

		if (Helper.testRand(planets,planetsL))	{
			// Learn values are at 0 by default, but can be changed when stored
			// Here if planets < planetsL (= 0 if nothing learned yet)
			// In case of equality the value is choosen randomly
			if (Helper.testRand(ships,shipsL))
				defend(pw);
			else
				attack(pw,1);	// 1 is for "planet attack"
		}
		else {
			if (Helper.testRand(growth,growthL)){
				if (Helper.testRand(fleet,fleetL))
					defend(pw);
				else
					attack(pw,0);	// 0 is for "GR attack"
			}
			else {
				if (Helper.testRand(ships,shipsL)){
					if (Helper.testRand(fleet,fleetL))
						defend(pw);
					else
						attack(pw,2);	// 2 is for destroying the ennemy ships to prevent him to conquer any of our planets
				}
				else
					attack(pw,3);	// 3 is for an attack that makes an overall winning (Dcalculation + distance)
			}
		}
	}