static void Main(string[] args)
        {
            Console.WindowHeight = 51;
            Console.BufferHeight = 51;
            Console.WindowWidth = 150;
            Console.BufferWidth = 150;
            CoordinateSystem();
            GraphInput();
            Console.ReadLine();
        }

        static void GraphInput()
        {
            //kx+m
            Console.SetCursorPosition(0, 0);
            Console.ForegroundColor = ConsoleColor.Gray;
            string stringK = null;
            string stringM = null;
            Console.WriteLine("Förstagradsgrafritaren v1\n");
            Console.WriteLine("Mata in din graf (kx+m)");
            Console.Write("\ny = ");
            string graph = Console.ReadLine().ToLower();


            foreach (char c in graph)
            {
                if (c == 'x')
                {

                    break;
                }

               stringK += c;
            }
            string check = null;
            foreach (char c in graph)
            {

                check += c;
                if (check.Contains('+') || check.Contains('-') && check.Contains(stringK) && check.Contains('x'))
                {
                    stringM += c;
                }
            }
            //-1x+3
            string check2 = null;
            string stringM2 = null;
            if (stringM.Contains('x'))
            {
                foreach (char c in stringM)
                {
                    check2 += c;
                    if (check2.Contains('+') || check2.Contains('-'))
                    {
                        stringM2 += c;
                    }
                }
            }

            int k = Int32.Parse(stringK);
            int m;
            if (stringM2 == null)
            {
                 m = Int32.Parse(stringM);
            }

            else
            {
                m = Int32.Parse(stringM2);
            }
            CreateGraph(k, m);

            GraphMenu();
        }

        static void CreateGraph(int k, int m)
        {
            m = Dot.y0 - m;

            Dot skärY = new Dot(Dot.x0, m);
            Dot.graph[0] = skärY;

            int indexCounter = 1;
            //Alla punkter som har x > 0
            for (int i = 1; i < 50; i++)
            {
                    Dot.graph[indexCounter] = new Dot(Dot.x0 + i, m - (k * i));
                    indexCounter++;

            }
            //Alla punkter som har x < 0
            for (int i = 1; i < 51;i++)
            {
                    Dot.graph[indexCounter] = new Dot(Dot.x0 - i, m + (k * i));
                    indexCounter++;
            }

            GraphOutput();
        }

        static void GraphOutput()
        {

            for (int i = 0; i < Dot.graph.Length; i++)
            {
                if (Dot.graph[i] != null && Dot.graph[i].posY > 0 && Dot.graph[i].posY < Console.WindowHeight && Dot.graph[i].posX > 0 && Dot.graph[i].posX < Console.WindowWidth)
                {
                    Dot.graph[i].PrintDot();
                }

            }


        }

        static void GraphMenu()
        {
            Console.ForegroundColor = ConsoleColor.Gray;
            PrintStringAt("1: Nytt koordinatsystem", 0, 6);
            PrintStringAt("2: Lägg till en graf i samma koordinatsystem", 0, 7);
            PrintStringAt("Val: ", 0, 9);
            string val = Console.ReadLine();
            switch (val)
            {
                case "1":
                    Restart();
                    break;
                case "2":
                    ConsoleClearArea(0, 0, 25, 5);
                    ConsoleClearArea(0, 6, 43, 9);
                    Console.SetCursorPosition(0, 0);
                    GraphInput();
                    break;
            }
        }

        //Vilket x den ska börja ifrån, vilket x den ska sluta på och vilken y den ska börja på och vilken y den ska sluta på.
        static void ConsoleClearArea(int xStart, int yStart, int xEnd, int yEnd)
        {
            for (int i = yStart; i <= yEnd; i++)
            {

                for (int j = xStart; j <= xEnd; j++)
                {
                    Console.SetCursorPosition(j, i);
                    Console.Write(" ");
                }
            }

        }

        static void Restart()
        {
            Console.Clear();
            CoordinateSystem();
            GraphInput();
        }

        static void PrintStringAt(string text, int x, int y)
        {
            Console.SetCursorPosition(x, y);
            Console.Write(text);
        }

        static void CoordinateSystem()
        {
            //X-axeln
            for (int i = 0; i < Console.WindowWidth; i++)
            {
                Console.SetCursorPosition(i, Dot.y0);
                Console.Write("■");
            }
            //Y-axeln
            for (int i = 0; i < Console.WindowHeight; i++)
            {
                Console.SetCursorPosition(Dot.x0, i);
                Console.Write("■");

            }
        }

    }

    class Dot
    {
        public static int x0 = Console.WindowWidth / 2;
        public static int y0 = Console.WindowHeight / 2;
        public static Dot[] graph = new Dot[101];
        public int posX;
        public int posY;

        public Dot(int posX, int posY)
        {
            this.posX = posX;
            this.posY = posY;
        }

        public void PrintInfo()
        {
            Console.WriteLine("posX: {0}, posY: {1}", posX, posY);
        }

        public void PrintDot()
        {
            Console.ForegroundColor = ConsoleColor.Red;
            Console.SetCursorPosition(posX, posY);
            Console.Write("■");
        }
    }

    class Globals
    {

    }