#include<fstream>
using namespace std;
int main()
{
	ifstream in("fact.in");
    ofstream out("fact.out");
	unsigned long p,cc=0,pp,n;
	in>>p;
	if(p!=0) 
	{
		for(n=5;cc<=p;n+=5)
		{
			pp=n;
			while(pp%5==0)		
			{
				cc++; 
				pp/=5;
			}if(cc==p) break;
		}
	if(cc==p) 
		out<<n<<"\n";
	else 
		out<<"-1"<<"\n";
	}
	else 
		out<<"1"<<"/n";
	out.close();
	in.close();
	return 0;
}