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

string s;
ll cnt[26];

void solve()
{
	const int n = s.length();
	ll ans = 1LL*n*(n-1)/2;
	for(int i=0;i<n;++i){
		ans -= cnt[s[i]-'a'];
		cnt[s[i]-'a']++;
	}
	cout << ans+1 << '\n';
}

int main()
{
	cin >> s;
	solve();
	return 0;
}
### Prompt

Please provide a CPP coded solution 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;
using ll = long long;

string s;
ll cnt[26];

void solve()
{
	const int n = s.length();
	ll ans = 1LL*n*(n-1)/2;
	for(int i=0;i<n;++i){
		ans -= cnt[s[i]-'a'];
		cnt[s[i]-'a']++;
	}
	cout << ans+1 << '\n';
}

int main()
{
	cin >> s;
	solve();
	return 0;
}
```