The objective of this puzzle to place the largest possible number of coins at points of eight-pointed star shown in the figure below. The coins should be placed one after another, with the following restrictions :

  • A needs to be placed first on an unoccupied point then moved along a line to another unoccupied point.
  • Once the coin has been positioned in this manner, it can not be moved again.

For example, we can start by placing the first coin on point 6 then moving it to point 1 (denoted 6 --> 1), where the coin will have to remain. We can continue, say, with the following sequence of moves : 7 --> 2, 8 --> 3, 7--> 4, 8 --> 5, which places five coins.

What is the largest possible number of coins that can be placed at points of eight-pointed star?

The Answer is an integer. Just put the number without any decimal places.