i := 1;
while not eoln(stroka) do
begin
  if storka[i]<>' ' then
  begin
    rezStroka := rezStroka + stroka[i];
    inc(i);
    if (lenght(rezStroka)>5)and (lenght(rezStroka)<8) then
      break;
  end
  else
  begin
    rezStroka := '';
    inc(i);
  end;
end;