#include <fstream>
using namespace std;
int main ()
{
	ifstream fin("fact.in");
	ofstream fout("fact.out");
	long n=0,p,x=0;
	fin>>p;
	if (p==0){fout<<"1"<<'\n'; return 0;} 
	if (p%6==5){fout<<"-1"<<'\n'; return 0;}
	while (x<p)
		{n=n+5;
		 if (n%39625==0) x=x+8;
			 else if(n%78125==0) x=x+7;
					 else if (n%15625==0) x=x+6;
							 else if (n%3125==0) x=x+5;
									 else if (n%625==0) x=x+4;
											 else if (n%125==0) x=x+3;
													 else if (n%25==0) x=x+2;
															  else x=x+1;
		}
	fout<<n<<'\n';
	return 0;
}