using System;

using System.Collections.Generic;

using System.Diagnostics.CodeAnalysis;

​

public class Program

{

    public static void Main()

    {

        //for the given array of points the result should be 2

        var result = new Ray().solution(new Point2D[]{new Point2D{x = -1, y = -2}, new Point2D{x = 1, y = 2}, new Point2D{x = 2, y = 4}, });

        Console.WriteLine(result);

    }

}

​

public class Ray

{

    //do not change the method signature

    public int solution(Point2D[] A)

    {

        var sortedPointsFirstAndSecondSector = new SortedList<Point2D, Point2D>(new PointCompararer());

        var sortedPointsThirdAndForthSector = new SortedList<Point2D, Point2D>(new PointCompararer());

        var isOxPositiveIncluded = false;

        var isOxNegativeIncluded = false;

        foreach (var point in A)

        {

            if (point.y == 0)

            {

                if (point.x > 0)

                {

                    isOxPositiveIncluded = true;

                }

​

                if (point.x < 0)

                {

                    isOxNegativeIncluded = true;

                }

            }

            else if (point.y > 0)

            {

                if (sortedPointsFirstAndSecondSector.ContainsKey(point))

                {

                    continue;

                }

​

                sortedPointsFirstAndSecondSector.Add(point, point);

            }

            else

            {

                if (sortedPointsThirdAndForthSector.ContainsKey(point))

                {

                    continue;

                }

​

                sortedPointsThirdAndForthSector.Add(point, point);

            }

        }

​

        return sortedPointsFirstAndSecondSector.Keys.Count + sortedPointsThirdAndForthSector.Keys.Count + (isOxPositiveIncluded ? 1 : 0) + (isOxNegativeIncluded ? 1 : 0);

    }

}

​

public class PointCompararer : IComparer<Point2D>

{

    public int Compare([AllowNull] Point2D first, [AllowNull] Point2D second)

    {

        return first.x * second.y == first.y * second.x ? 0 : first.x * second.y > first.y * second.x ? -1 : 0;

    }

}

​

public class Point2D

{

    public long x;

    public long y;

}