Problem:
Score : 300 points

Problem Statement

Given is a string S. Let T be the concatenation of K copies of S.
We can repeatedly perform the following operation: choose a character in T and replace it with a different character.
Find the minimum number of operations required to satisfy the following condition: any two adjacent characters in T are different.

Constraints

1 \leq |S| \leq 100

S consists of lowercase English letters.

1 \leq K \leq 10^9

K is an integer.

Input

Input is given from Standard Input in the following format:

S
K

Output

Print the minimum number of operations required.

Sample Input 1

issii
2

Sample Output 1

4

T is issiiissii. For example, we can rewrite it into ispiqisyhi, and now any two adjacent characters are different.

Sample Input 2

qq
81

Sample Output 2

81

Sample Input 3

cooooooooonteeeeeeeeeest
999993333

Sample Output 3

8999939997

Solution in Scala (2.11.7) (judge verdict: Wrong Answer)

object Main {
  def main(args: Array[String]) = {
    val sc = new java.util.Scanner(System.in)
    val s = sc.next
    val k = sc.nextLong
    sc.close()

    val ss = matcher(s ++ s)
    val ans = ss.count(_ == '_') * k / 2
    println(ans)
  }

  import scala.collection.mutable
  def matcher(xs: String): mutable.Buffer[Char] = {
    val buf = xs.toBuffer
    (1 until buf.length).foreach(i => {
      if (buf(i - 1) == buf(i)) {
        buf.update(i, '_')
      }
    })
    buf
  }
}