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 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

int64_t power(int64_t a, int64_t b) {
    int64_t tmp = b;
    int64_t base = 1;
    
    while(tmp > 0) {

        if((tmp % 2) == 0){
            a *= a;
            tmp >>= 1;
        } else {
            base *= a;
            tmp--;
        }

    }
    return base;
}

int main(int argc, char *argv[]) {
    char buf[16];
    char *p;
    int N,K;
    int64_t pattern;

    p = fgets(buf, 16, stdin);
    
    (void)sscanf(buf, "%d %d", &N, &K);

    pattern = power((K-1),(N-1)) * K;
    printf("%ld\n", pattern);

    return 0;
}