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 Python (3.4.3) (judge verdict: Wrong Answer)

A = input()
l = len(A)
count = 1 + l*(l-1)//2

for i in range(l):
    if i == 0:
        continue
    
    j = 0
    while i-j:
        if A[i+j] == A[i-j-1]:
            count -= 1
            j += 1
            if i+j == l:
                j = 0
                break
        else:
            j = 0
            break
    else:
        j = 0
        
    while i-j-1:
        if A[i+j] == A[i-j-2]:
            count -= 1
            j += 1
            if i+j == l:
                j = 0
                break
        else:
            j = 0
            break
    else:
        j = 0

print(count)