#include <stdio.h>

#define MOD(x) ((x) % 1000000000000)

int main()
{
	long long N;
	scanf("%lld", &N);

	long long n = 1;
	for (long long i = 2; i <= N && n; i++)
		n = MOD(n * i);

	if (N < 15)
		printf("%lld\n", n);
	else// if (N < 50)
		printf("%012lld\n", n);
	return 0;
}