import tensorflow as tf

    # Implement an exponential learning rate decay every 1000 epochs

    #Implement a dynamical learning rate
    global_step = tf.Variable(0., trainable=False)
    rate = tf.train.exponential_decay(starter_learning, global_step, 500, 0.9) #exponential learning rate decay
    #rate = starter_learning

    tvars = tf.trainable_variables() #list of trainable variables
