public class Urna {
	public static void main(String[] args) {

		double y = Math.random();
		public Urna() { c = 0; }
		public Urna(Color c) { c = y; }
		private int n_blancas, n_negras;
		private double c;

		// double Math.random() generates a number between 0 and 1

		Urna blanca = new Urna(0);
		Urna negra = new Urna(1);


		public void introducirBola(Color c) {
			if (c == blanca) {
			n_blancas += 1;
			}3
			else if (c == negra) {
			n_negras += 1;
			}
		}

		public Color sacarBola() {
			c = double Math.random();
					if (c == blanca) {
			n_blancas -= 1;
			}
			else if (c == negra) {
			n_negras -= 1;
			}
			return Color;
		}

		public boolean estaVacia {
			if (totalBolas() == 0)
			return True;
		}

		public int totalBolas() {
			return n_negras + n_blancas;
		}

	}