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

int main() {
long long a[26]={0},n;
string s;
cin>>s;
n=s.length();
for(int i=0;i<n;i++){
    a[s[i]-'a']++;
}
n=n*(n-1)/2;
for(int i=0;i<26;i++){
    n-=a[i]*(a[i]-1)/2;
}
cout<<n+1<<endl;
	return 0;
}
### Prompt

Develop a solution in CPP to the problem described below:

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() {
long long a[26]={0},n;
string s;
cin>>s;
n=s.length();
for(int i=0;i<n;i++){
    a[s[i]-'a']++;
}
n=n*(n-1)/2;
for(int i=0;i<26;i++){
    n-=a[i]*(a[i]-1)/2;
}
cout<<n+1<<endl;
	return 0;
}
```