const
  delimiter = [#32, ',', '.', '!', ':'];
type
  wrd_info = record
    start, len: byte;
  end;

function get_words(s: string;
         var words: array of wrd_info; var diff: integer): integer;
var
  count: integer;

  i, j, curr_len: byte;
  found: boolean;

begin
  count := -1; i := 1; diff := 0;
  while i <= length(s) do begin

    while (s[i] in delimiter) and (i <= length(s)) do inc(i);

    curr_len := 0;
    while not (s[i] in delimiter) and (i <= length(s)) do begin
      inc(i); inc(curr_len);
    end;

    if curr_len > 0 then begin
      found := false;
      for j := 0 to count do
        if copy(s, words[j].start, words[j].len) =
           copy(s, i - curr_len, curr_len) then found := true;

      if not found then inc(diff);

      inc(count);
      with words[count] do begin
        start := i - curr_len;
        len := curr_len
      end;
    end;

  end;
  get_words := count + 1;
end;


const
  max_word = 255;
var
  words: array[1 .. max_word] of wrd_info;
  i, n, diff: integer;

const
  s: string = 'ogog,    thats,,, all :: foolks !!! bye foolks, bye...';
var
  T: string;
  j, count: integer;

begin
  n := get_words(s, words, diff);
  writeln('different words count: ', diff);

  for i := n downto 1 do begin
    T := copy(s, words[i].start, words[i].len);
    count := 0;
    for j := 1 to length(T) do
      inc(count, byte(T[j] = 'o'));

    if count = 2 then
      delete(s, words[i].start, words[i].len);
  end;
  writeln('s = ', s);
end.