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 cnt = 1
    var ope = 0
    for (i in 1 until s.size) {
        if (s[i - 1] == s[i]) {
            cnt += 1
        } else {
            ope += cnt / 2
            cnt = 1
        }
    }
    ope += cnt / 2
    var result = ope.toLong() * k
    if (s[0] == s[s.size - 1] && cnt % 2 == 0) {
        var j = 0
        while (s[j] == s[s.size - 1] && j < s.size - 1) {
            cnt += 1
            j += 1
        }
        if (cnt % 2 == 0) {
            result += k - 1
        }
    }
    println(result)
}