#include<bits/stdc++.h>
using namespace std;
char s[500000],c[500000];
long long sum[30];
int main() {
	scanf("%s",s);
	long long  n=strlen(s),ans=n*(n-1)/2+1;
	for(int j=0;j<n;j++)
		sum[s[j]-'a'+1]++;
	for(int i=1;i<=26;i++)
		ans-=sum[i]*(sum[i]-1)/2;
	cout<<ans;
}
### Prompt

Please create a solution in Cpp 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<bits/stdc++.h>
using namespace std;
char s[500000],c[500000];
long long sum[30];
int main() {
	scanf("%s",s);
	long long  n=strlen(s),ans=n*(n-1)/2+1;
	for(int j=0;j<n;j++)
		sum[s[j]-'a'+1]++;
	for(int i=1;i<=26;i++)
		ans-=sum[i]*(sum[i]-1)/2;
	cout<<ans;
}
```