#include <iostream>
#include <fstream>
using namespace std;
ifstream f("factorial.in");
ofstream g("factorial.out");
int cinci=0,p,n,k,cinci1;
int main ()
{
	f>>p;
	if (p==0)
		g<<"1";
else
{
	while (k<p)
	{
		cinci+=5;
		cinci1=cinci;
		while (cinci1%5==0)
		{
			k++;
			cinci1/=5;
		}
	}
	if (k==p)
		g<<cinci;
	else g<<"-1";
}
f.close();
g.close();
}