How Much Wire?

A farmer builds a barbed wire fence. He digs the holes and sets 10 posts in a straight line with 12-foot spaces between them. He then strings two lines of barbed wire between each of the posts, an upper wire and lower wire. Besides spanning the 12-foot gap between the posts each wire will also wrap around the 1-foot circumference of each post before continuing to the next (including the end posts). How many feet of wire will the farmer require?