You are given a 17x15 board with some positions marked black. The black squares are the possible positions of fence posts.
You will have to build a continuous loop of fence by clicking on these positions.

Click the board to randomize the setup. Numbers will appear at the right border indicating how many of each length of straight you have. Also, one red and two blue fence posts will appear at the main board. These are three corner posts of the fence you have to build. Your fence has to pass through these three positions.

You can only add fence pieces to the red fence post.
Click a fence post position to the north, east, south or west of the red post. A piece of fence will appear and the clicked position will now carry the red post.
After each move the corresponding length counter at the right border will decrease.

You cannot connect two vertical or two horizontal lengths.

You win when you have used up all lengths and your fence is one closed loop.

Click the botton at the top right border to see a solution.
Several correct solutions might be possible.

Please note there are three alternative piece sets.

 
This game was inspired by a mathematical problem stated in 2005 at the PQRST puzzle competition (http://www.otuzoyun.com/pqrst).