rvae = RVAE(parameters)
device_ids = [i for i in range(t.cuda.device_count())]
rvae = t.nn.DataParallel(rvae, device_ids)
rvae = rvae.cuda()
forward function is the following
rvae(0.,  encoder_word_input, encoder_character_input,
decoder_word_input, decoder_character_input,
z=None)