var
  s, ns:string;
  i, num10: integer;

function bin2dec(s:string):integer;
var
  nums: String;
  i:integer;
begin
   nums:='01';
   result:=0;
   for i:=1 to length(S) do
    result:=result+(pos(S[i],nums)-1)*round(Exp((length(S)-i)*Ln(2)));
end;

begin
  read(s);
  s := LowerCase(s);
  ns := '';

  i := 1;
  while (i < length(s) - 1) do // цикл по всей строке
  begin
    if ((i + 2 <= length(s)) and (s[i] = 'o') and (s[i + 1] = 'n') and (s[i + 2] = 'e')) then
    begin
      ns := ns + '1';
      i := i + 3;
    end
    else
    if ((i + 3 <= length(s)) and (s[i] = 'z') and (s[i + 1] = 'e') and (s[i + 2] = 'r') and (s[i + 3] = 'o')) then
    begin
      ns := ns + '0';
      i := i + 4;
    end
    else
      inc(i);
  end;

  writeln(IntToStr(bin2dec(ns)));
end.