#include<bits/stdc++.h>
using namespace std;
using ll = long long;

int main()
{
	string s;
	cin >> s;
	ll ans = 0;
	vector<int> v(26,0);
	for(auto c:s)
	{
		//cout<<c-'a'<<endl;
		v[c-'a']++;

		for(int i = 0;i<26;i++)
		{
			if(i+'a'==c)continue;
			ans += v[i];
		}
		//cout<<ans<<endl;
	}
	cout<<ans+1<<endl;
}
### Prompt

Construct a cpp code solution to the problem outlined:

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;
using ll = long long;

int main()
{
	string s;
	cin >> s;
	ll ans = 0;
	vector<int> v(26,0);
	for(auto c:s)
	{
		//cout<<c-'a'<<endl;
		v[c-'a']++;

		for(int i = 0;i<26;i++)
		{
			if(i+'a'==c)continue;
			ans += v[i];
		}
		//cout<<ans<<endl;
	}
	cout<<ans+1<<endl;
}
```