# include <fstream.h>
int main ()
{
	int p,n=0,ok,j=0,i,q=0;
	ifstream f("fact.in");
	ofstream g("fact.out");
	f>>p;
	ok=0;
	for (i=5;ok==0;i=i+5)
	{	j=i;
		while (j%625==0 &&j!=0) {n+=4;j/=625;}
		while (j%125==0 && j!=0) {n+=3;j/=125;}
		while (j%25==0 && j!=0) {n+=2;j/=25;}
		while (j%5==0 && j!=0) {n+=1;j/=5;}
		if (n==p) {ok=1;q=i;}
	}
	g<<q;
	f.close ();
	g.close ();
	return 0;
}