#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
char s[2000500];
int n;
LL F[30],ans;
int main() {
	scanf("%s",s+1);
	n = strlen(s+1);
	for (int i=1;i<=n;i++) {
		F[ s[i]-'a' ]++;
		for (int j=0;j<26;j++) if (j != s[i]-'a') ans += F[j];
	}
	cout << ans+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 <bits/stdc++.h>
using namespace std;
typedef long long LL;
char s[2000500];
int n;
LL F[30],ans;
int main() {
	scanf("%s",s+1);
	n = strlen(s+1);
	for (int i=1;i<=n;i++) {
		F[ s[i]-'a' ]++;
		for (int j=0;j<26;j++) if (j != s[i]-'a') ans += F[j];
	}
	cout << ans+1 << endl;
	return 0;
}
```