#include<fstream.h>
ifstream f("fact.in");
ofstream g("fact.out");
long p,k;
void radacina(long x,long &k)
{if(x%10==5||x%10==0) 
		{k++;radacina(x/5,k);}
}
int main()
{f>>p;
if(p==0)
   g<<1;
else
	{long nf=0,nr=0;
     while(k<p) 
	 {nf+=5;radacina(nf,k);}
	 if(k==p)
		 g<<nf;
	 else
		 g<<-1;
}
return 0;
}