Problem:
Score : 200 points

Problem Statement

There are N balls placed in a row.
AtCoDeer the deer is painting each of these in one of the K colors of his paint cans.
For aesthetic reasons, any two adjacent balls must be painted in different colors.

Find the number of the possible ways to paint the balls.

Constraints

1≦N≦1000

2≦K≦1000

The correct answer is at most 2^{31}-1.

Input

The input is given from Standard Input in the following format:

N K

Output

Print the number of the possible ways to paint the balls.

Sample Input 1

2 2

Sample Output 1

2

We will denote the colors by 0 and 1. There are two possible ways: we can either paint the left ball in color 0 and the right ball in color 1, or paint the left in color 1 and the right in color 0.

Sample Input 2

1 10

Sample Output 2

10

Since there is only one ball, we can use any of the ten colors to paint it. Thus, the answer is ten.

Solution in OCaml (4.02.3) (judge verdict: Accepted)

let () =
  let n,k = Scanf.scanf "%d %d " (fun a b -> a,b) in
  let pow a n =
    let rec aux res a n =
      if n = 0 then res else aux (res*a) a (n-1)
    in
    aux 1 a n
  in
  Printf.printf "%d\n" @@
  pow (k-1) (n-1) * k