import tensorflow as tf

        enc_outputs, enc_state = tf.nn.rnn(cell, inp, dtype=tf.float32)
        attn_states = tf.concat(1, [tf.reshape(e, [-1, 1, cell.output_size])
                                    for e in enc_outputs])
        dec_inp = [tf.constant(0.4, shape=[2, 2])] * 3
        dec, mem = tf.nn.seq2seq.attention_decoder(
            dec_inp, enc_state,
