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

function fget_array($dlmt = null) {
    $input = trim(fgets(STDIN));
    return $dlmt ? explode($dlmt, $input) : str_split($input);
}

$s = fget_array();
$k = fget_array(' ')[0];

$limit = count($s) - 1;
$cnt = 0;
$all = true;
for ($i = 0, $c = $s[0]; $i < $limit; $i++) {
    $next = $s[$i + 1];
    if ($s[$i] !== $next) $all = false;
    if ($next === $c) {
        $cnt++;
        $c = '';
    } else {
        $c = $next;
    }
}

$offset = 0;
if ($limit > 1 && $s[0] === $s[$limit]) {
    if (empty(in_array($s[0], [$s[1], $s[$limit - 1]]))) $offset = $k - 1;
    if ($all) $offset++;
}

echo $cnt * $k + $offset;
?>