#include <fstream.h>
int p,i,ok;
long int n,nc;
int main ()
{
ifstream in("fact.in");
in >>p;
in.close ();
n=0;
ok=1;
if (p)
do
{
n=n+5;
nc=n;
while (nc%5==0)
      {
      i++;
      nc=nc/5;
      }
if (i>p)
   ok=0;
} while (i<p);
else
   n=1;
ofstream out("fact.out");
if (ok==1)
   out <<n;
else
   out <<-1;
out.close ();
return 0;
}