using System;
using System.Collections;

public struct Point : IComparable<Point> {
    private int x;
    private int y;

    public Point(int x, int y) {
        this.x = x;
        this.y = y;
    }

    public override String ToString() {
        return "(" + x + ", " + y + ")";
    }

    public int CompareTo(Point other) {
        double d = Math.Sqrt((x - other.x) * (x - other.x) +
                             (y - other.y) * (y - other.y));
        if (d < 0)
            return -1;
        else if (d == 0)
            return 0;
        else // d > 0
            return 1;
    }

    public int X {
        get { return x; }
        set { x = value; }
    }

    public int Y {
        get { return y; }
        set { y = value; }
    }

    public static Point operator+(Point p1, Point p2) {
        return new Point(p1.x + p2.x, p1.y + p2.y);
    }
}

public class Example {
    public static void Main() {
        Point p1 = new Point();
        Console.WriteLine("p1 = " + p1);
        int sum = p1.X + p1.Y;
        p1.X = 3;
        p1.X++;
        p1.Y = 19;
        Console.WriteLine("p1 = " + p1);
        Point p2 = new Point(7, 8);
        Point p3 = p1 + p2;
        Console.WriteLine("p2 = " + p2);
        Console.WriteLine("p3 = " + p3);

        Point[] points = {new Point(3, 4), new Point(8, 2), new Point(0, 5),
                          new Point(2, 0), new Point(2, 2)};
        Array.Sort(points);
        Console.WriteLine(points);
        foreach (Point p in points)
            Console.WriteLine(p);
    }
}