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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.

### Sample Input 1

aatt


### Sample Output 1

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 $A[1..3]$).

### Sample Input 2

xxxxxxxxxx


### Sample Output 2

1


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

### Sample Input 3

abracadabra


### Sample Output 3

44