7krokods — COCI CONTEST_#4
Task type: batch | Time limit: 1 s | Memory limit: 512 MB | Difficulty: 9
Algorithms: enumeration

# Task 7Krokods

When he is not making videos for his [YouTube channel](https://www.youtube.com/channel/UCLeaG05z_yu0xK4CyM8byuQ), the famous programmer influencer Krokod likes to play boardgames with his friend Paula. He wants to play the game *7Krokods*, but Paula doesn't like complex games, so Krokod decided that they will play only with green and crocodile cards.

Paula has $n$ green cards, and each of them has one of the following letters written on it: d, k, o, or r. Her total score is defined as the sum of the following components:

* For each letter, she gets as many points as the number of cards with that letter written on them, squared. For example, if she has 6 cards with the letter k, she gets 36 points.
* For each word krokod she can make from her cards, she gets an extra 7 points.

*Illustration of the first example.*

Paula has 2 letters d ($2 \cdot 2 = 4$ points), 6 letters k ($6 \cdot 6 = 36$ points), 4 letters o ($4 \cdot 4 = 16$ points) and 3 letters r ($3 \cdot 3 = 9$ points). The word *krokod* can be spelled 2 times ($7 \cdot 2 = 14$ points). Her total score is 79. ($4 + 36 + 16 + 9 + 14 = 79$)

Paula also has $m$ crocodile cards. She can replace each of the crocodile cards with a green card having a letter of her choice. She will do it in a way that maximizes her score.

Help her determine the maximum score she can get with her cards.

## Input

The first line contains integers $n$ and $m$ ($0 \le n \le 100$, $0 \le m \le 10$), the number of green cards and the number of crocodile's cards.

The second line contains a sequence of $n$ characters, where the $i$-th characters represents the letter on the $i$-th green card. The sequence consists only of characters d, k, o and r.

## Output

In the first and only line output Paula's maximum possible score.

## Scoring

| Subtask | Points | Constraints               |
| :------ | :----- | :------------------------ |
| 1       | 17     | $m = 0$                   |
| 2       | 26     | $m = 1$                   |
| 3       | 7      | No additional constraints |

#### Examples

| Input                   | Input   | Input   |
| :---------------------- | :------ | :------ |
| 15 0                    | 5 1     | 8 2     |
| krokodkrokodkrk          | rokod   | ddkkoorr |
| Output                  | Output  | Output  |
| 79                      | 17      | 35      |

#### Clarification of the first example:

Look at the illustration in the task statement.

#### Clarification of the second example:

For the maximum possible score, Paula can replace her crocodile card with a green card having the letter k.

Starter code: