#include <iostream>
using namespace std;

int main(){
	string s;
	cin >> s;
	int64_t a[26]{};
	for(char c:s) a[c - 'a']++;
	int64_t n = s.size(), ans = n * (n - 1) / 2 + 1;
	for(int i = 0; i < 26; i++){
		ans -= a[i] * (a[i] - 1) / 2;
	}
	cout << ans << endl;
}
### Prompt

Generate 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>
using namespace std;

int main(){
	string s;
	cin >> s;
	int64_t a[26]{};
	for(char c:s) a[c - 'a']++;
	int64_t n = s.size(), ans = n * (n - 1) / 2 + 1;
	for(int i = 0; i < 26; i++){
		ans -= a[i] * (a[i] - 1) / 2;
	}
	cout << ans << endl;
}
```