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# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Q01
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            long k = Int64.Parse(Console.ReadLine());
            long count = 0;
            bool startend = false;
            for (int i = 0; i < s.Length; i++)
            {
                if(i == s.Length -1)
                {
                    startend = (s[i] == s[0]) && (s[0] != s[1]);
                }
                else if (s[i] == s[i + 1])
                {
                    count++;
                    i++;
                }
            }
            count = count * k;
            if (startend)
            {
                count += k - 1;
            }
            Console.WriteLine(count);

            //Console.ReadKey();
        }
    }
}