Jimmy invents an interesting card game. There are N cards, each of which contains a string Si. Jimmy wants to stick them into several circles, and each card belongs to one circle exactly. When sticking two cards, Jimmy will get a score. The score of sticking two cards is the longest common prefix of the second card and the reverse of the first card. For example, if Jimmy sticks the card S1 containing "abcd" in front of the card S2 containing "dcab", the score is 2. And if Jimmy sticks S2 in front of S1, the score is 0. The card can also stick to itself to form a self-circle, whose score is 0.
For example, there are 3 cards, whose strings are S1="ab", S2="bcc", S3="ccb". There are 6 possible sticking:
1. S1->S2, S2->S3, S3->S1, the score is 1+3+0 = 4
2. S1->S2, S2->S1, S3->S3, the score is 1+0+0 = 1
3. S1->S3, S3->S1, S2->S2, the score is 0+0+0 = 0
4. S1->S3, S3->S2, S2->S1, the score is 0+3+0 = 3
5. S1->S1, S2->S2, S3->S3, the score is 0+0+0 = 0
6. S1->S1, S2->S3, S3->S2, the score is 0+3+3 = 6
So the best score is 6.
Given the information of all the cards, please help Jimmy find the best possible score.