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
$str = str();
$n = int();
$p = $str[0];
$count = 1;
for($i = 1; $i < strlen($str); $i++){
  if($str[$i] != $str[$i-1]){
    $numArray[] = $count;
    $count = 0;
  }
  $count++;
}
if($count != 0){
  $numArray[] = $count;
}
if(count($numArray) == 1){
  echo floor(strlen($str) * $n / 2);
}elseif($str[0] == $str[-1]){
  $sum = 0;
  foreach($numArray as $num){
    $sum+=floor($num/2);
  }
  $l = $numArray[0];
  $r = $numArray[count($numArray)-1];
  $diff = floor(($r+$l)/2) - floor($l/2) - floor($r/2); 
  echo $sum * $n + $diff * ($n-1);
}else{
  $sum = 0;
  foreach($numArray as $num){
    $sum+=floor($num/2);
  }
  echo $sum * $n;
}



function str(){
  return trim(fgets(STDIN));
}
function int(){
  return intval(trim(fgets(STDIN)));
}
function o(...$val){
    if(count($val)==1)$val = array_shift($val);
    $trace = debug_backtrace();
    echo $trace[0]['line'].")";
    if(is_array($val)){
        if(count($val) == 0){
            echo "empty array";
        }elseif(!is_array(current($val))){
            echo "array:";
            echo implode(" ", $val)."\n";
        }else{
            echo "array:array\n";
            foreach($val as $row){
                echo implode(" ", $row)."\n";
            }
        }
    }else{
        echo $val."\n";
    }
}