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>

int main(void) {
	char s[110];
	long int n;
	long int count=0;
  	long int tmp;
	int i=0;

	scanf("%s",&s);
	scanf("%ld",&n);
	
	while(s[i+1]!=0||s[i]!=0){
		if(s[i]==s[i+1]){
			count++;
			i=i+2;
		}else{
			i++;
		}
	}
	count=count*n;

	if(s[0]==s[i]){
		count=count+(n-1);
	}
  if(s[1]==0){
  	count=count+(n)/2;
  }else{
    count=count;
  }
  i=1;
  while(s[i]!=0){
	if(s[i]==s[i-1]){
      tmp=1;
      i++;
    }else{
      tmp=0;
      break;
    }
  }
    if(tmp==1){
	tmp=(i*n)/2;
		if(count>tmp){
			count=tmp;
		}
    }
  printf("%ld",count);
	
return 0;
}