#!/bin/python

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

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