 So, where are we reached so far from the beginning of aviation till date okay. So, you can see this information has come from Boeing. The Boeing 747-100 was launched somewhere in the mid 60s and the productivity as measured in passenger miles per gallon was approximately 60. You can see that there is a 50% improvement in the productivity in about 1995 in the introduction of Boeing 747-400. So with every version of the aircraft there has been a consistent improvement in the productivity. Let us see how this compares with a typical force passenger automobile at 24 miles per gallon. The productivity of that is actually far, far lower. So if you want to have an idea about these novel configurations, why they are provided, what their benefits are, there are some good textbooks which are recommended. The book by Darrell Stanton on the anatomy of the airplane is a good book for information designed for air combat by Ray Wittford. It is also a very good book and actually the book has a much larger focus than the title. Reimers textbook has two chapters which are dedicated to configuration layout and also on unique aircraft concepts. And then Jan Roscombe has a series of books on aircraft design chapter 3 has one section 3.3 on unusual configurations in particular. Some closing notes, you might see many configurations which are very unique and so you might think that all has already been investigated but no, there is still enough room for dreamer. Remember there is a time and place for everything and if you can somehow justify what you are providing as a configuration you can have it. Thanks for your attention, we will now move to the next section.