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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.Scanner;
import java.util.Arrays;
import java.util.ArrayList;

class Main{
  
  	static int check = -1;
	public static void main(String[] args){
      	Scanner sc = new Scanner(System.in);
      	String line = sc.nextLine();
      	long n = sc.nextLong();
      
      	
     	long count;
      	long c = 0l;
      	if(line.length() > 1){
          count = count(line);
          c = count2(line);
      	  System.out.println(count*n + c*(n-1));
        }else{
          if(n == 1){
            System.out.println(0);
          }else{
             String l = line;
             for(int i = 0; i < n-1; i++) l += line;
             count = count(l);
             c = count2(l);
             System.out.println(count+c);
          }
        }
    }
  
  	static long count(String line){
    	long count = 0;
      	int i = 1;
    	while(i <= line.length()-1){
          System.out.println(i);
    		if(line.charAt(i) == line.charAt(i-1)){
              count++;
              i += 2;
              check = i;
            }else{
              i++;
            }
    	}
    	return count;
    }
  
  	static long count2(String line){
    	return (line.length() > 2 && 
                (check == line.length()) &&
                line.charAt(0) == line.charAt(line.length()-1)) ? 1: 0;
    }
}