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 Java (OpenJDK 1.8.0) (judge verdict: Wrong Answer)


import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		char[] str = sc.next().toCharArray();
		int k = sc.nextInt();;

		if(str.length == 1){
			System.out.println(k/2);
			return;
		}
		int changeCount = 0;
		for(int i = 1; i < str.length; i++){
			if(str[i] == str[i - 1]){
				changeCount++;
				str[i] = 'A';
			}
		}
//		System.out.println(changeCount);
		long result = (long)k*changeCount;

		if(str[0] == str[str.length - 1]){
			result += k - 1;
		}
		System.out.println(result);
	}

}