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