2-Letter Strings

Description:

Input:

The first line of the input contains a single integer $$$t$$$ ($$$1 \le t \le 100$$$) — the number of test cases. The description of test cases follows.

The first line of each test case contains a single integer $$$n$$$ ($$$1 \le n \le 10^5$$$) — the number of strings.

Then follows $$$n$$$ lines, the $$$i$$$-th of which containing a single string $$$s_i$$$ of length $$$2$$$, consisting of lowercase Latin letters from 'a' to 'k'.

It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$10^5$$$.

Output:

For each test case, print a single integer — the number of pairs $$$(i, j)$$$ ($$$i < j$$$) such that the $$$i$$$-th string and the $$$j$$$-th string have exactly one position $$$p$$$ ($$$1 \leq p \leq 2$$$) such that $$${s_{i}}_{p} \neq {s_{j}}_{p}$$$.

Please note, that the answer for some test cases won't fit into 32-bit integer type, so you should use at least 64-bit integer type in your programming language (like long long for C++).

Sample Input:

4
6
ab
cb
db
aa
cc
ef
7
aa
bb
cc
ac
ca
bb
aa
4
kk
kk
ab
ab
5
jf
jf
jk
jk
jk

Sample Output:

5
6
0
6

Note:

For the first test case the pairs that differ in exactly one position are: ("ab", "cb"), ("ab", "db"), ("ab", "aa"), ("cb", "db") and ("cb", "cc").

For the second test case the pairs that differ in exactly one position are: ("aa", "ac"), ("aa", "ca"), ("cc", "ac"), ("cc", "ca"), ("ac", "aa") and ("ca", "aa").

For the third test case, the are no pairs satisfying the conditions.