public class Difficult {
    protected static int[] buffer;
    protected static int width = 40;
    protected static int height = 40;

  private static void draw_line(int x, int y, int xx, int yy) {
    for(int sy = y; sy <= yy; sy++) {
      for(int sx = x; sx <= xx; sx++) {
        buffer[sy * height + sx] = 1;
      }
    }
  }

  public static void main(String [] args) {
    int speed = 1;
    int x = width / 2;
    int y = height / 2;
    buffer = new int[width*height];
    for(int i = 0; i < height - 4; i++) {
      int dir = i % 4;
      switch(dir) {
        // up
        case 0:
          draw_line(x, y-speed, x, y);
          y -= speed;
          break;
        // left
        case 1:
          speed += 2;
          draw_line(x-speed, y, x, y);
          x -= speed;
          break;
        // down
        case 2:
          draw_line(x, y, x, y+speed);
          y += speed;
          break;
        // right
        case 3:
          speed += 2;
          draw_line(x, y, x+speed, y);
          x += speed;
          break;
      }
    }
    // draw
    for(int sy = 0; sy < height; sy++) {
      for(int sx = 0; sx < width; sx++) {
        if (buffer[sy*height+sx] == 1)
          System.out.print("█");
        else
          System.out.print(" ");
      }
      System.out.print("\n");
    }
  }
}