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 Python (3.4.3) (judge verdict: Wrong Answer)

def main():
    S = input()
    K = int(input())
    ans = 0

    if len(S) is 1:
        print(K // 2)
        return

    if len(set(S)) is 1:
        print(len(S) * K // 2)
        return

    i = 0
    while i < len(S) - 1:
        if S[i] is S[i + 1]:
            ans += 1
            i += 1
        i += 1

    if ans is 0 and S[0] is S[-1]:
        print(K - 1)
    else:
        print(ans * K)


if __name__ == "__main__":
    main()