atcoder#AGC039A. [AGC039A] Connection and Disconnection

[AGC039A] Connection and Disconnection

Score : 300300 points

Problem Statement

Given is a string SS. Let TT be the concatenation of KK copies of SS. We can repeatedly perform the following operation: choose a character in TT and replace it with a different character. Find the minimum number of operations required to satisfy the following condition: any two adjacent characters in TT are different.

Constraints

  • 1S1001 \leq |S| \leq 100
  • SS consists of lowercase English letters.
  • 1K1091 \leq K \leq 10^9
  • KK is an integer.

Input

Input is given from Standard Input in the following format:

SS

KK

Output

Print the minimum number of operations required.

issii
2
4

TT is issiiissii. For example, we can rewrite it into ispiqisyhi, and now any two adjacent characters are different.

qq
81
81
cooooooooonteeeeeeeeeest
999993333
8999939997