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## 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 ≤ i ≤ j ≤ 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.

## Limits

For all subtasks: `1 ≤ |A| ≤ 200,000`. `A` consists of lowercase English letters.

Subtask 1 (11%): `1 ≤ |A| ≤ 100`

Subtask 2 (48%): `1 ≤ |A| ≤ 2000`

Subtask 3 (41%): No additional contraints

Subtask 4 (0%): Sample Testcases

## 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

### Tags

### Subtasks and Limits

Subtask | Score | #TC | Time | Memory | Scoring |
---|---|---|---|---|---|

1 | 11 | 5 | 1s | 256MB | Minimum |

2 | 48 | 5 | 1s | 256MB | Minimum |

3 | 41 | 5 | 1s | 256MB | Minimum |

4 | 0 | 3 | 1s | 256MB | Minimum |

### Judge Compile Command

g++-7 ans.cpp -o reversecompare -Wall -static -O2 -lm -m64 -s -w -std=gnu++17 -fmax-errors=512