//
class HTree
{

  public static void DrawHTree (int x, int y, int length, int depth) {
    if (length == 0) {
      return;
    }

    DrawHTree(x, y, length, depth, 0);
  }

  public static void DrawHTree (int x, int y, int length, int depth, int currentDepth) {
    if (depth == currentDepth) {
      return;
    }

    int halfLength = length / 2; // 1

    int xLeft   = x - halfLength; // -1
    int xRight  = x + halfLength; // 1
    int yTop    = y + halfLength;  // 1
    int yBottom = y - halfLength; // -1

    DrawLine(xLeft,    y,  xRight, y); // (-1,0) -> (1,0)
    DrawLine(xLeft, yTop,  xLeft,  yBottom); // (-1,1) -> (-1,-1)
    DrawLine(xRight, yTop, xRight, yBottom); // (1, 1) -> (1,-1)

    int newLength = length / Math.Sqrt(2);
    currentDepth++;

    DrawHTree(xLeft,  yTop, newLength, currentDepth); // (-1,1) 1
    DrawHTree(xLeft,  yBottom, newLength, currentDepth); // (-1,-1)  1
    DrawHTree(xRight, yTop, newLength, currentDepth); //
    DrawHTree(xRight, yBottom, newLength, currentDepth);
  }

  public static void DrawLine(int x1, int y1, int x2, int y2) {
    Console.WriteLine("(" + x1 + "," + y1 + ")");
    Console.WriteLine("(" + x2 + "," + y2 + ")");
  }

// if (depth == givenLength) { // 0, 1, 2
   //return;
//}

// halfLength = length / 2 => 1
// (x - halfLength, y) (x + halfLength, y)
// (x + halfLength, y + halfLength)  (x + halfLength, y - halfLength)
// (x - halfLength, y + halfLength)  (x - halfLength, y - halfLength)

// drawHTree (x + halfLength, y + halfLength, length/Sqrt(2), depth)

// drawHTree (x + halfLength, y - halfLength, length/Sqrt(2), depth)
//drawHTree (x - halfLength, y + halfLength, length/Sqrt(2), depth)
  //drawHTree (x - halfLength, y - halfLength, length/Sqrt(2), depth)
    static void Main()
    {
        System.Console.WriteLine("Practice makes Perfect!");
    }
}

// x, y  (0,0)   length (2)
// if (depth == givenLength) { // 0, 1, 2
   //return;
//}

// halfLength = length / 2 => 1
// (x - halfLength, y) (x + halfLength, y)
// (x + halfLength, y + halfLength)  (x + halfLength, y - halfLength)
// (x - halfLength, y + halfLength)  (x - halfLength, y - halfLength)

// drawHTree (x + halfLength, y + halfLength, length/Sqrt(2), depth)
// drawHTree (x + halfLength, y - halfLength, length/Sqrt(2), depth)
//drawHTree (x - halfLength, y + halfLength, length/Sqrt(2), depth)
//drawHTree (x - halfLength, y - halfLength, length/Sqrt(2), depth)
  O(4^d)  -> 1 + 4 + 4 * 4 + ... + 4^(depth - 1) = 4^depth - 1 /(4- 1)= O(4^depth)