Problem:
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

Solution in PHP (5.6.30) (judge verdict: Time Limit Exceeded)

<?php
error_reporting(0);
//list($Q,$H,$S,$D) = explode(" ",trim(fgets(STDIN)));
$A = trim(fgets(STDIN));
$len=strlen($A);
$result=0;
for($i=0;$i<$len;$i++) {
  for($j=$i;$j<$len;$j++) {
    if ($j==$i) continue;
    if ($A[$j]!=$A[$i]) {
      $result++;
    }
  }
}
printf("%d\n",$result+1);