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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main()
{
    char str[105];
    scanf("%s", str);
    long long int k;  scanf("%lld", &k);
    int len = strlen(str);
    long long int count = 0, count1 = 0;
    if(len==1)
    {
        printf("%lld\n", k/2);
        return 0;
    }
    for(int i=1; i<len; i++)
    {
        if(str[i]==str[i-1])
        {
            count++;
            str[i]='5';
        }
    }
    if(str[0]==str[len-1])
        count1++;
    long long ans = count*k + count1*(k-1);
    printf("%lld\n", ans);
    return 0;
}