type sir=array[1..1000000] of boolean;
var a,b:sir;
    n,nr,x,i,p,j:longint;
    f,g:text;
begin
 assign(f,'fractii.in'); reset(f);
 assign(g,'fractii.out'); rewrite(g);
 read(f,n);
 x:=n;
 nr:=0;
 for j:=1 to x do begin
  n:=j; a:=b;
  p:=2;
  if n mod p=0 then
   for i:=1 to x div 2 do
    a[i*2]:=true;
  while (n<>1) and (n mod p=0) do
   n:=n div 2;
  p:=3;
  while n<>1 do begin
   if n mod p=0 then
    for i:=1 to x div p do
     a[i*p]:=true;
   while (n<>1) and (n mod p=0) do
    n:=n div p;
   inc(p,2);
  end;
  for i:=1 to x do
   if a[i]=false then
    nr:=nr+1;
 end;
 writeln(g,nr);
 close(f); close(g);
end.