Problem Statement
We will call a string obtained by arranging the characters contained in a string $a$ in some order, an anagram of $a$.
For example, greenbin is an anagram of beginner. As seen here, when the same character occurs multiple times, that character must be used that number of times.
Given are $N$ strings $s_1, s_2, \ldots, s_N$. Each of these strings has a length of $10$ and consists of lowercase English characters. Additionally, all of these strings are distinct. Find the number of pairs of integers $i, j$ $(1 \leq i < j \leq N)$ such that $s_i$ is an anagram of $s_j$.
Constraints
$2 \leq N \leq 10^5$$s_i$is a string of length$10$.- Each character in
$s_i$is a lowercase English letter. $s_1, s_2, \ldots, s_N$are all distinct.
Input
Input is given from Standard Input in the following format:
N
s_1
s_2
:
s_N
Output
Print the number of pairs of integers $i, j$ $(1 \leq i < j \leq N)$ such that $s_i$ is an anagram of $s_j$.
样例
3
acornistnt
peanutbomb
constraint
1
2
oneplustwo
ninemodsix
0
5
abaaaaaaaa
oneplustwo
aaaaaaaaba
twoplusone
aaaabaaaaa
4
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