#include<fstream>
using namespace std;
int main()
{unsigned long long n, p, r;
ifstream f("fact.in");
ofstream h("fact.out");
f>>p;
if (p==0)
	n=1;
else
{p=p-1;
r=1;
while (p!=0)
{r=r*5;
p=p-r;}
n=r*5;
}
h<<n<<endl;

f.close();
h.close();
return 0;
}