content_image/311158.jpg content_image/311159.jpg content_image/311160.jpg content_image/311161.jpg
Since 

<img src='content_image/311158.jpg'>

and 

<img src='content_image/311159.jpg'>

we have 

Finally, the boundary term is obtained as follows: 

<img src='content_image/311160.jpg'>

<img src='content_image/311161.jpg'>

