AT_abc393_b [ABC393B] A..B..C

A string $ S $ is given. Find how many places in $ S $ have `A`, `B`, and `C` in this order at even intervals. Specifically, find the number of triples of integers $ (i,j,k) $ that satisfy all of the following conditions. Here, $ |S| $ denotes the length of $ S $ , and $ S_x $ denotes the $ x $ -th character of $ S $ . - $ 1 \leq i < j < k \leq |S| $ - $ j - i = k - j $ - $ S_i = $ `A` - $ S_j = $ `B` - $ S_k = $ `C`

The input is given from Standard Input in the following format: > $ S $

Print the answer.

### Sample Explanation 1 There are two triples $ (i,j,k) = (1,3,5) $ and $ (2,3,4) $ that satisfy the conditions. ### Constraints - $ S $ is an uppercase English string with length between $ 3 $ and $ 100 $ , inclusive.