#include<fstream>
using namespace std;
long int p,r,i,j;
int main()
{
	ifstream f("fact.in");
	ofstream g("fact.out");
	f>>p;
	if(p==0)
	{
		g<<1;
		return 0;
	}
	for(i=5;;i+=5)
	{
		j=i;
		while(j%5==0){j=j/5;r++;}
		if(r==p){g<<i;break;}
		if(r>p){g<<"-1";break;}
	}
	return 0;
}