The beavers are hospitable and they like visit each other.
However, sometimes they are not at home.
Therefore, they need to leave a message for their guests using an informational gate.
The beavers has come up with 4 different messages, as follows:
 |
We are at home.
Please come in. |
 |
We will come back
at noon. |
 |
We will come back
in the evening. |
 |
We will be back
at midnight. |
However, Little Beaver Cheolsoo thinks it is possible to make up more than 4 messages by changing the place of these logs.
He knows that the logs must meet the following conditions:
– The logs can only either be attached horizontally, or be removed completely.
– The shape and orientation of the logs are not important.
But he does not know exactly how many messages are possible.
What is the maximum number of messages that are possible, including the 4 original messages?
|