#Lutece2644. 友好回文串

友好回文串

Migrated from Lutece 2644 友好回文串

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Description

若一个字符串翻转后等于自身,则称之为回文串。

两个回文串的友好值为 xx,是指存在一个长度为 xx 的回文串,是这两个回文串的公共前缀。且不存在长度大于 xx 的回文串,是这两个回文串的公共前缀。

给出一个字符串 SS。求 SS 的所有回文子串(出现位置不同但相等的回文串视为同一个回文子串)两两友好值之和。

Input

仅一行,字符串 SSSS 仅包含小写字母。

Output

仅一行,表示友好值之和。

Samples

aba
1
aabaa
7

Constraints

1S5×1051 \le |S| \le 5\times 10^5

Note

对于样例 2,SS 的所有回文子串为 $\{\texttt a,\texttt{aa},\texttt b,\texttt{aba},\texttt{aabaa}\}$。

$$\begin{aligned} (\texttt a,\texttt{aa})=1\\ (\texttt a,\texttt b)=0\\ (\texttt a,\texttt{aba})=1\\ (\texttt a,\texttt{aabaa})=1\\ (\texttt{aa},\texttt b)=0\\ (\texttt{aa},\texttt{aba})=1\\ (\texttt{aa},\texttt{aabaa})=2\\ (\texttt b,\texttt{aba})=0\\ (\texttt b,\texttt{aabaa})=0\\ (\texttt{aba},\texttt{aabaa})=1 \end{aligned} $$

总和为 77

Resources

2021 UESTC ICPC Training for String and Search Algorithm