include<bits/stdc++.h>

using namespace std; int main() {

int n,i,jc=1;
cin>>n;
for(i=1;i<=n;i++)
{
	jc*=i;
	while(jc%10==0)
		jc/=10;
	jc%=10000; //当我被冯领导追杀时
}
cout<<jc%10;
return 0; //雪花飘飘(～o￣3￣)～

}//完美趋势