#include<iostream>
#include<cstdio>
#include<vector>
using namespace std;
string a;
int s[26];
long long ans;
int main()
{
	cin>>a;
	for(int i=0;i<a.size();i++)
	{
		for(int j=0;j<26;j++)
		{
			if(a[i]-'a'==j)continue;
			ans+=s[j];
		}
		s[a[i]-'a']++;
	}
	printf("%lld",ans+1);
	return 0;
}
### Prompt

Your challenge is to write 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>
#include<cstdio>
#include<vector>
using namespace std;
string a;
int s[26];
long long ans;
int main()
{
	cin>>a;
	for(int i=0;i<a.size();i++)
	{
		for(int j=0;j<26;j++)
		{
			if(a[i]-'a'==j)continue;
			ans+=s[j];
		}
		s[a[i]-'a']++;
	}
	printf("%lld",ans+1);
	return 0;
}
```