#include<fstream>
using namespace std;
int main ()
{long n,p,c,e,b;
ifstream f("fact.in");
ofstream h("fact.out");
f>>p;
c=0;e=0;
if(p==0)
n=1;
else
{do
{c=c+5;
b=c;
while(b%5==0)
{e=e+1;
b=b/5;}}
while(e<p);
if(e==p)
h<<c;
else
h<<-1;}  
f.close();
h.close();
return 0;}