#include <stdio.h>
#include <math.h>


int factorial(int n, int cumulative_product, int multiplier,int p)
{
	
long int next;
long int running_product;
long int total;


if (multiplier != 1)
{
next=n-1;
running_product= (cumulative_product* next );
running_product= factorial(n-1, running_product, next, p);
cumulative_product= running_product;
}
else
next=1; 

total=cumulative_product;	

return(total);
}


	
	
int main(void)
{

long int product, half, p;


scanf("%i", &p);

half= (p-1);
product= p*factorial(half, half, half-1, p);
	
printf("Product =%i\n", product)	;

}