#include <bits/stdc++.h>

using namespace std;

const int N = 2e5 + 5;

char s[N];
int cnt[26];

int main() {
  scanf("%s", s);
  int n = strlen(s);
  long long ans = 1;
  for (int i = n - 1; i >= 0; i--) {
    ans += (n - i - 1) - cnt[s[i] - 'a'];
    cnt[s[i] - 'a']++;
  }
  cout << ans << endl;
  return 0;
}

### Prompt

In CPP, your task is to solve 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;

const int N = 2e5 + 5;

char s[N];
int cnt[26];

int main() {
  scanf("%s", s);
  int n = strlen(s);
  long long ans = 1;
  for (int i = n - 1; i >= 0; i--) {
    ans += (n - i - 1) - cnt[s[i] - 'a'];
    cnt[s[i] - 'a']++;
  }
  cout << ans << endl;
  return 0;
}

```