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 Kotlin (1.0.0) (judge verdict: Wrong Answer)

fun main(args : Array<String>) {
    val S = readLine()!!.toCharArray()
    val K = readLine()!!.toLong()


    var tailHeadSame = S.first() == S.last()
    var singleDups = 0L

    if (S.size == 1) {
        println(K /2)
        return
    }

    var prev = ' '
    var other = 0L
    for (i in 0 until S.size) {
        if (i == S.size - 1 && tailHeadSame && K != 1L) {
            other++
        } else if (S[i] == prev) {
            S[i] = 'X'
            singleDups++
        }
        prev = S[i]
    }

    println(
            singleDups * K + other * (K-1)
    )
}