using System;

using System.Linq;

using System.Collections.Generic;

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);

        var result2 = new Ray().solution(new Point2D[] {

            new Point2D { x = -1, y = -2 },

            new Point2D { x = 1, y = 2 },

            new Point2D { x = 2, y = 4 },

            new Point2D { x = -2, y = -4 },

            new Point2D { x = 5, y = 5 },

            new Point2D { x = 1, y = 1 },

            new Point2D { x = -2, y = -2 },

        });

        Console.WriteLine(result2);

    }

}

​

public class Ray

{

    //do not change the method signature

    public int solution(Point2D[] A)

    {

        //TODO: write your solution

        //we can ue angles

        List<double> coss = new List<double>();

        foreach(Point2D point in A)

        {

            //we calculate the angle for each point

            var h = Math.Sqrt(point.x * point.x + point.y * point.y);

            var cos = point.x / h;

            //if there is no such cos then the ray has to be added, otherwise the point can be hit by an existing ray

            //having positive and negative numbers doesn't mater because the angle is not affected

            if(!coss.Contains(Math.Abs(cos))) { 

                coss.Add(cos);

            }

        }

        return coss.Count;

    }

}

​

public class Point2D

{

    public long x;

    public long y;

}

​