#!/bin/python3

import sys

def fact(n):
    if n==1:
        return 1
    else:
        return n*fact(n-1)
    
def countArray(n, k, x):
    temp = fact(k-1)
    temp *= (n-2)
    if x<=k:
        return temp-1
    else:
        return temp

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