#include<fstream.h>

unsigned long p,n,e,i,d,c,ok;

int main()
{  ifstream fin("fact.in");
   ofstream fout("fact.out");
   fin>>p;
   if(p==0) n=1;
   else
   {
   c=5;
   ok=1;
   for(i=5;i<=c&&ok;i+=5)
   {   d=i;
       while(d%5==0)
       { d/=5;
	 e++;
       }
       if(e==p)
		{ n=i;
		  ok=0;
		}
      c+=5;
   }
   }
   if(ok==0)fout<<n;
      else fout<<-1;
   fin.close();
   fout.close();
   return 0;
}