Submit solution

Points:
7 (partial)

Time limit:
1.8s

Memory limit:
256M

Author:

Problem type

Allowed languages

Ada, Assembly, Awk, Brain****, C, C#, C++, COBOL, ~~CommonLisp~~, D, Dart, F#, Forth, Fortran, Go, ~~Groovy~~, Haskell, Intercal, Java, JS, Kotlin, Lisp, Lua, ~~Nim~~, ~~ObjC~~, OCaml, ~~Octave~~, Pascal, Perl, PHP, Pike, Prolog, Python, Racket, Ruby, Rust, Scala, Scheme, Sed, Swift, TCL, Text, Turing, VB, Zig

Mimi is playing with a string when her little sister asks her a question:

How many substrings of are there such that these substrings are of length and have exactly 1 distinct letter?

#### Constraints

Let denote the length of .

For all subtasks, .

##### Subtask 1 [10%]

##### Subtask 2 [90%]

#### Input Specification

The first line of input will contain a single string, , consisting of only lowercase English letters.

The second line of input will contain an integer, .

#### Output Specification

The number of substrings which satisfy the given condition.

#### Sample Input

```
aaaabb
2
```

#### Sample Output

`4`

## Comments