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 C++14 (GCC 5.4.1) (judge verdict: Runtime Error)

#include <iostream>
#include <set>
#include <string>
using namespace std;
string getRever(const string &A,int I,int J)
{
	string A1=A;
	int i,j;
	j=I;
	for (i=J;i>=I;i--){
		A1[j++]=A[i];
	}
	return A1;
}
int main(int argc, char* argv[])
{
	string A;
	cin>>A;
	int strLen=A.size();
	int i,j;
	char ch=A[0];
	bool bSame=true;
	for (i=0;i<strLen;i++){
		if (A[i] != ch){
			bSame=false;
		}
	}
	if (bSame){
		cout<<1<<endl;
		return 0;
	}
	string A1;
	set<string> setStr;
	for (i=0;i<strLen-1;i++){
		for (j=i+1;j<strLen;j++){
			A1=getRever(A,i,j);
			setStr.insert(A1);
		}
	}
	cout<<setStr.size()<<endl;
	return 0;
}