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 Ruby (2.3.3) (judge verdict: Wrong Answer)

s = gets.chomp
k = gets.to_i
n = s.length
if n == 1
  p k/2
else
  ans = 0
  if s[0] == s[n-1]
    ans += k
    s[n-1] = (n-1 % 10).to_s
  end
  1.upto(n-1) do |i|
    if s[i] == s[i-1]
      s[i] = (i % 10).to_s
      ans += k
    end
  end
  p ans
end