#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

void comb(int num, int i, long long int rez)
{
	if (num != 1)
	{
		num--;
		rez = rez * i;
		comb(num, i, rez);
	}
	else printf("%lld", rez);
}

int main()
{
	int n,m;
	scanf("%d", &n);
	m = n;
	comb(n, n, m);
	return 0;
}