P3047 [CF1902E] Collapsing Strings
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题目描述

You are given $n$ strings $s_1, s_2, \dots, s_n$, consisting of lowercase Latin letters. Let $|x|$ be the length of string $x$.

Let a collapse $C(a, b)$ of two strings $a$ and $b$ be the following operation:

  • if $a$ is empty, $C(a, b) = b$;
  • if $b$ is empty, $C(a, b) = a$;
  • if the last letter of $a$ is equal to the first letter of $b$, then $C(a, b) = C(a_{1,|a|-1}, b_{2,|b|})$, where $s_{l,r}$ is the substring of $s$ from the $l$-th letter to the $r$-th one;
  • otherwise, $C(a, b) = a + b$, i. e. the concatenation of two strings.

Calculate $\sum\limits_{i=1}^n \sum\limits_{j=1}^n |C(s_i, s_j)|$.

Input

The first line contains a single integer $n$ ($1 \le n \le 10^6$).

Each of the next $n$ lines contains a string $s_i$ ($1 \le |s_i| \le 10^6$), consisting of lowercase Latin letters.

The total length of the strings doesn't exceed $10^6$.

Output

Print a single integer — $\sum\limits_{i=1}^n \sum\limits_{j=1}^n |C(s_i, s_j)|$.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
3 aba ab ba
样例输出
20