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?

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.

Constraints

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

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

见题面 Input 部分

见题面 Output 部分