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 PyPy3 (2.4.0) (judge verdict: Wrong Answer)

s = input()
k = int(input())
n = len(s)
p = ['']*(4*n)
for i in range(n):
    p[i] = s[i]
    p[i+n] = s[i]
    p[i+2*n] = s[i]
    p[i+3*n] = s[i]

a = [0,0,0,0]

for i in range(1,4*n):
    if p[i] == p[i-1]:
        a[i//n] += 1
        p[i] = ''
print((k//4)*sum(a) + sum(a[:k%4]))