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 C (Clang 3.8.0) (judge verdict: Accepted)

#include <stdio.h>

int main() {
    int n, k;
    scanf("%d %d", &n, &k);

    if (n == 1) {
        printf("%d\n", k);
        return 0;
    }
    if (k == 2) {
        printf("%d\n", k);
        return 0;
    }

    unsigned long long r = k;
    for (int i = 2; i <= n; i++) {
        r *= (k-1);
    }

    printf("%lld\n", r);

    return 0;
}