Score : $500$ points

Problem Statement

You have a string $A = A_1 A_2 ... A_n$ consisting of lowercase English letters.

You can choose any two indices $i$ and $j$ such that $1 \leq i \leq j \leq n$ and reverse substring $A_i A_{i+1} ... A_j$.

You can perform this operation at most once.

How many different strings can you obtain?

Constraints

• $1 \leq |A| \leq 200,000$
• $A$ consists of lowercase English letters.

Input

Input is given from Standard Input in the following format:

$A$

Output

Print the number of different strings you can obtain by reversing any substring in $A$ at most once.

aatt

5

You can obtain aatt (don't do anything), atat (reverse $A[2..3]$), atta (reverse $A[2..4]$), ttaa (reverse $A[1..4]$) and taat (reverse $A[1..3]$).

xxxxxxxxxx

1

Whatever substring you reverse, you'll always get xxxxxxxxxx.

abracadabra

44