import java.util.Scanner;

public class Vector
{
	private double x = 0;
	private double y = 0;

	public Vector()
	{
	}

	public Vector(double x, double y)
	{
		this.x = x;
		this.y = y;
	}

	public boolean leer()
	{
		Scanner teclado = new Scanner(System.in);
		x = teclado.nextDouble();
		y = teclado.nextDouble();
		return x != 0 && y != 0;
	}

	public String toString()
	{
		return String.format("(x, y) = (%s, %s); (r, θ) = (%s, %s)"
			, format(x), format(y), format(magnitud()), format(angulo()));
	}

	public static String format(double valor)
	{
		return (long)valor == valor
			? String.format("%,d", (long)valor)
			: String.format("%.2f", valor);
	}

	public double magnitud()
	{
		return Math.sqrt(x*x + y*y);
	}

	public double angulo()
	{
		return Math.atan2(y, x);
	}

	public Vector sumar(Vector otro)
	{
		return new Vector(x + otro.x, y + otro.y);
	}

	public Vector restar(Vector otro)
	{
		return new Vector(x - otro.x, y - otro.y);
	}

	public static void main(String[] args)
	{
		Vector vector1 = null;
		Vector vector2 = new Vector();

		System.out.println("Operaciones con vectores en el plano");
		for (long i = 1; ; ++i)
		{
			System.out.print("\nVector " + i + ": ");
			if ( ! vector2.leer() )
				return;
			System.out.println("V" + i + ": " + vector2);

			if ( vector1 != null )
			{
				System.out.printf("\nV%d + V%d: %s\n", i - 1, i, vector1.sumar(vector2)  );
				System.out.printf("V%d - V%d: %s\n",   i - 1, i, vector1.restar(vector2) );
				System.out.printf("V%d - V%d: %s\n",   i, i - 1, vector2.restar(vector1) );
			}
			vector1 = vector2;
			vector2 = new Vector();
		}
	}
}