var f,g:text;
    p,k,nr,n,x,aux:longint;
begin
assign(f,'fact.in');
reset(f);
assign(g,'fact.out'); rewrite(g);
readln(f,p);
if p>0 then begin
       k:=5;
       nr:=1;
       while nr<p do begin
        k:=k+5;   aux:=k;
        while (k mod 5=0) and (k<>0) do begin
                  k:=k div 5;
                  inc(nr);
                  end;
                  k:=aux;
              end;
            if nr>p then k:=-1;
         end
         else k:=1;
write(g,k);
close(g);
close(f);
end.