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 Go (1.6) (judge verdict: Runtime Error)

package main

import (
	"fmt"
	"os"
	"strings"
)

func main() {
	// fmt.Println(8999939997 / 999993333)
	var s string
	var k int
	fmt.Scan(&s, &k)
	ss := strings.Split(s, "")
	var p string
	var count int
	// var j int
	var j = 1
	var f bool
	var fs string
	for i, c := range ss {
		if c == p && i != 0 {
			count++
			f = true
		} else {
			if f {
				j++
			}
			f = false
		}
		p = c
		if len(s)-1 == i {
			fs = c
		}
	}
	// fmt.Println(fs)
	// fmt.Println(count, j)
	var r int
	if j == 0 {
		fmt.Println(k * count)
		os.Exit(0)
	}
	if s[0:1] == fs {
		r = count / (j - 1)
	} else {
		r = (count / (j - 1)) + 1
	}
	fmt.Println(k * r)
}

// cooooooooonteeeeeeeeeest