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 Pascal (FPC 2.6.2) (judge verdict: Accepted)

var cc : array ['a'..'z',0..200000] of longint ;
    a,b,c,d,e,f,g,h,i,j : longint ;
    so :ansistring ;
    gg : char ;
    sum : int64 ;
begin
 readln(so);
 j:=length(so);
 for a:=1 to j do
  cc[so[a],a]:=cc[so[a],a]+1;
 for gg:='a' to 'z' do
  for a:=1 to j do
   begin
    cc[gg,a]:=cc[gg,a]+cc[gg,a-1];
   end;
  for a:=2 to j do
   begin
    sum:=sum+(a-(cc[so[a],a]-1)-1);
 //   writeln(cc[so[a],a],' ',cc[so[a],a-1]);
   end;
  writeln(sum+1);
end.