program TongSoChiaHetCho3;
var
  num, sum: integer;
begin
  sum := 0;
  write('Nhap mot day so (ket thuc nhap 0): ');
  readln(num);
  while num <> 0 do
  begin
    if num mod 3 = 0 then
      sum := sum + num;
    readln(num);
  end;
  writeln('Tong cac so chia het cho 3 la: ', sum);
end.