#include<fstream.h>
ifstream f("fact.in");
ofstream g("fact.out");
void perm(unsigned long &fif, unsigned long p)
{
unsigned long sir=1;
while(sir<p)
	{sir=sir*5+1;
	 fif-=fif/sir;}
}
int main()
{
unsigned long p,fife=0,fif;
f>>p;
if(!p)
 g<<1;
else
{fif=p;fife=p+1;
 perm(fif,p);
 perm(fife,p+1);
 if(fife!=fif)
  g<<5*fif;
 else
  g<<-1;
}
return 0;
}