#include <iostream>
#include <string.h>
using namespace std;
typedef long long LL;
LL MAX=999999999999;
int main(int argc, char* argv[])
{
	LL N;
	cin>>N;
	int i;

	LL v=1;
	for (i=2;i<=N;i++){
		v=v*i;
		if (v>MAX){
			char p[100];
			sprintf(p,"%lld",v);
			char *p1=p+strlen(p)-12;
			char *p2=p1;
			bool allZero=true;
			while (*p2!='\0'){
				if (*p2!='0'){
					allZero=false;
					break;
				}
				p2++;
			}
			if (allZero==true){
				cout<<"000000000000"<<endl;
				return 0;
			}
			sscanf(p1,"%lld",&v);
		}
	}
	cout<<v<<endl;
	return 0;
}