#include <iostream>
#include <string>
using namespace std;

int main(){
    string A;
    cin >> A;

    int cnt[27];
    for(char i='a';i<='z';i++) cnt[i-'a']=0;

    long long ptn=1;
    for(int i=0;i<A.size();i++){
        ptn+=i-cnt[A[i]-'a'];
        cnt[A[i]-'a']++;
    }

    cout << ptn << endl;
}
### Prompt

Your challenge is to write a Cpp solution to the following problem:

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.

Examples

Input

aatt


Output

5


Input

xxxxxxxxxx


Output

1


Input

abracadabra


Output

44

### Response

```cpp
#include <iostream>
#include <string>
using namespace std;

int main(){
    string A;
    cin >> A;

    int cnt[27];
    for(char i='a';i<='z';i++) cnt[i-'a']=0;

    long long ptn=1;
    for(int i=0;i<A.size();i++){
        ptn+=i-cnt[A[i]-'a'];
        cnt[A[i]-'a']++;
    }

    cout << ptn << endl;
}
```