public static void main(String[] args) throws InterruptedException {
        final int numberOfTrees = 10;
        final int numberOfDucks = 10;
        final int numberOfHunters = 10;
        HuntField f = new HuntField(15, 20);
        for (int i = 0; i < numberOfTrees; i++) {
            new Tree(f);
        }
        for (int i = 0; i < numberOfDucks; i++) {
            new Duck(f).start();
        }
        for (int i = 0; i < numberOfHunters; i++) {
            new Hunter(f).start();
        }
        while (f.getNumberOfItems('D') > 0) {
            Thread.sleep(200);
            printField(f);
        }
        printField(f);
    }