#!/bin/python3

import sys
def fact(m):
    if m==0 or m==1:
        return 1
    else:
        return m*fact(m-1)
      
def countArray(n, k, x):
    # Return the number of ways to fill in the array.
    p=n-2
    fp=fact(p)
    fk=fact(k)
    fkp=fact(k-p)
   
    res=fk//fp*fkp
    return res

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)