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

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