#include<fstream>
using namespace std;

int main() {
	
	int p,i,k,nr=0;
	
	ifstream in("fact.in");
	ofstream out("fact.out");
	in>>p;
	
	if(p==0)
		out<<"1";
	else {
		
		for(i=5;nr<p;i+=5) {
			k=i;
	
			while(k%5==0) {
				k/=5;
				nr++;
				}
			}
		
		if(nr>p)
			out<<"-1";
		else
			out<<i-5;
		}
	
	out<<'\n';
	
	in.close();
	out.close();
	
	return 0;
	
}