var
  s:string;
  i,n,x,r,j,m:longint;
begin
  assign(input,'bita.in');
  assign(output,'bita.out');
  reset(input);
  rewrite(output);
  readln(n);
  for i:=1 to n do
    begin
      x:=i;
      s:='';
      while x>0 do
        begin
          r:=x mod 2;
          s:=s+chr(r+ord('0'));
          x:=x div 2;
        end;
      for j:=length(s)-1 downto 1 do
        if (s[j]='1')and(s[j+1]='1') then m:=m+1;
   end;
   writeln(m);
   close(input);
   close(output);
end.