#!/bin/python3

import sys
import math

def countArray(n, k, x):
    tmp_fact = math.factorial(k-2) 
    if k < x :
        return tmp_fact * k
    else :    
        return (tmp_fact * (k-1) * 2) - tmp_fact

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)