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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

// inputに入力データ全体が入る
function Main(input) {
	// 1行目がinput[0], 2行目がinput[1], …に入る
	input = input.split("\n");
	S = input[0];
	//K = input[1];
	var k = parseInt(input[1], 10);
	n = S.length;
	//console.log(S,k,n);
	
	
	 S1=[];
	var cnt =0;var f = 0;
	for(i=0;i<n;i++){if( S.substr(i,1)==S.substr(i+1,1)){f++;
	                                                   //  S1[i] =f;
	                                                     }
	                              else if(f > 0){S1[i-f] =f+1;
	                              f = f/2;
	                                            f = Math.ceil(f);
	                                            cnt = cnt + f;
                                                var f = 0;
	                                         //   S1[i]=f;
	                                            }
                                                         else{S1[i]=f+1;}
	                       }
//	console.log(i,cnt,f);
//	console.log(S1);
	if(S.substr(0,1)==S.substr(n-1,1)){ 
	                                   if(S[0]%2 ==1 && S[n-1]%2==1)
	                                                   { cnt=cnt+7-1;}}
	   
	
	//console.log(cnt);
	//console.log(cnt*k);
	if (n==1){cnt = Math.ceil(cnt*k/2);}else{cnt = cnt*k;}  
	console.log(cnt);   
	}
//*この行以降は編集しないでください（標準入出力から一度に読み込み、Mainを呼び出します）
Main(require("fs").readFileSync("/dev/stdin", "utf8"));