import tensorflow as tf

    input_training_masks = tf.placeholder(tf.float32, shape=[None, None, None, 1], name='input_training_masks')

    global_step = tf.get_variable('global_step', [], initializer=tf.constant_initializer(0), trainable=False)
    learning_rate = tf.train.exponential_decay(FLAGS.learning_rate, global_step, decay_steps=10000, decay_rate=0.94, staircase=True)
