#!/bin/python

import sys
import math

def countArray(n, k, x):
    # Return the number of ways to fill in the array.
    value=math.factorial(k)/math.factorial(k-1)
    return value

if __name__ == "__main__":
    n, k, x = raw_input().strip().split(' ')
    n, k, x = [int(n), int(k), int(x)]
    answer = countArray(n, k, x)
    print answer