Cakes

You have 'N' cakes of different names. You want to choose exactly 3 cakes out of these 'N' cakes. The name of the ith cake is 'S[i]' (0 <= i < 'N'). The three chosen cakes should follow the following conditions.

The name of the cake should start with 'c', 'a', 'k', 'e', or 's'.
No two cakes should begin with the same letter.

Return the number of ways to choose three cakes irrespective of the order.

Note : Assume 0-based indexing.

For example:

Let 'N' = 4, S = ["choco", "apple", "kesar", "strawberry"].
There exist 4 different ways to choose three cakes following all the required conditions i.e. {"choco", "apple", "kesar"}, {"choco", "apple", "strawberry"}, {"choco", "strawberry", "kesar"}, {"strawberry", "apple", "kesar"}.

Input Format:-

The first line contains an integer 'T', which denotes the number of test cases.
For every test case:-
The first line contains only one integer 'N' the number of cakes.
The second line contains 'N' space-separated strings denoting the elements of the 'S'. 

Output Format:-

For each test case, return the number of ways to choose three cakes irrespective of the order.

Note:-

You don’t need to print anything. Just implement the given function.

Constraints:-

1 <= 'T' <= 10
1 <= 'N' <= 10^4
0 <= |S[i]| <= 10
All the names of cakes are distinct and consist of lowercase letters.

Time Limit: 1 sec