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

int main() {
	string a;
	cin >> a;
	int count[26] = {0};
	long long ans = 1;
	for(int i=0;i<a.size();i++) {
		int c = a[i] - 'a';
		ans += i - count[c];
		count[c]++;
	}
	cout << ans << endl;
	return 0;
}

### Prompt

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

int main() {
	string a;
	cin >> a;
	int count[26] = {0};
	long long ans = 1;
	for(int i=0;i<a.size();i++) {
		int c = a[i] - 'a';
		ans += i - count[c];
		count[c]++;
	}
	cout << ans << endl;
	return 0;
}

```