Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ACM-ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

No tag edit access

I. Palindrome Pairs

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard outputAfter learning a lot about space exploration, a little girl named Ana wants to change the subject.

Ana is a girl who loves palindromes (string that can be read the same backwards as forward). She has learned how to check for a given string whether it's a palindrome or not, but soon she grew tired of this problem, so she came up with a more interesting one and she needs your help to solve it:

You are given an array of strings which consist of only small letters of the alphabet. Your task is to find how many palindrome pairs are there in the array. A palindrome pair is a pair of strings such that the following condition holds: at least one permutation of the concatenation of the two strings is a palindrome. In other words, if you have two strings, let's say "aab" and "abcac", and you concatenate them into "aababcac", we have to check if there exists a permutation of this new string such that it is a palindrome (in this case there exists the permutation "aabccbaa").

Two pairs are considered different if the strings are located on different indices. The pair of strings with indices $$$(i,j)$$$ is considered the same as the pair $$$(j,i)$$$.

Input

The first line contains a positive integer $$$N$$$ ($$$1 \le N \le 100\,000$$$), representing the length of the input array.

Eacg of the next $$$N$$$ lines contains a string (consisting of lowercase English letters from 'a' to 'z') — an element of the input array.

The total number of characters in the input array will be less than $$$1\,000\,000$$$.

Output

Output one number, representing how many palindrome pairs there are in the array.

Examples

Input

3

aa

bb

cd

Output

1

Input

6

aab

abcac

dffe

ed

aa

aade

Output

6

Note

The first example:

- aa $$$+$$$ bb $$$\to$$$ abba.

The second example:

- aab $$$+$$$ abcac $$$=$$$ aababcac $$$\to$$$ aabccbaa
- aab $$$+$$$ aa $$$=$$$ aabaa
- abcac $$$+$$$ aa $$$=$$$ abcacaa $$$\to$$$ aacbcaa
- dffe $$$+$$$ ed $$$=$$$ dffeed $$$\to$$$ fdeedf
- dffe $$$+$$$ aade $$$=$$$ dffeaade $$$\to$$$ adfaafde
- ed $$$+$$$ aade $$$=$$$ edaade $$$\to$$$ aeddea

Codeforces (c) Copyright 2010-2019 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Mar/22/2019 16:21:05 (d1).

Desktop version, switch to mobile version.

Supported by

User lists

Name |
---|