Given an grid of letters, one can select four squares such that the first is a
the second is an
A, the third is an
L, and the last is an
I, and two adjacent squares in the pattern
share at least a corner.
This selection process is repeated as many times as possible, with the caveat that a given square can only be selected at most once.
Compute the maximum number of distinct sets of letters that can be selected.
In tests worth marks, you may assume .
In tests worth an additional marks, you may assume .
The first line of the input contains a single integer, .
The next lines contain characters, all of which appear in
Output, on a single line, the maximum number of sets that can be selected.
4 CALI ILAC CLLC IAAI