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 PHP7 (7.0.15) (judge verdict: Wrong Answer)

<?php
//error_reporting(0);
$S = trim(fgets(STDIN));
$K = trim(fgets(STDIN));
//list($N,$M) =  explode(" ",trim(fgets(STDIN)));
//$A = explode(" ",trim(fgets(STDIN)));
$len=strlen($S);
if ($len == 1) {
printf("%d\n",intval($K/2));
exit;
}
$rep=0;
for($i=1;$i<$len;$i++) {
  if ($S[$i-1]==$S[$i]) {
    $S[$i]='*';
    $rep++;
  }
}
if ($S[0]==$S[$len-1]) {
  printf("%d\n",$rep+($rep+1)*($K-1));
}
else {
  printf("%d\n",$rep*$K);
}