program fact;
var p,a,b,cont,i:longint;
    n:word;
    f:text;
 begin
 assign(f,'fact.in');
 reset(f);
 read(f,p);
 cont:=0;
 n:=0;
  for a:=1 to p do
  begin
   n:=n+1;
   b:=n;
   repeat
   if b mod 5=0 then
    begin
     cont:=cont+1;
     b:=b div 5
    end;
   until (b div 5)<>0;
   if cont=0 then
    cont:=1;
  end;
  assign(f,'fact.out');
  rewrite(f);
  write(f,cont);
  close(f);
 end.