import tensorflow as tf

    Returns:
    X -- placeholder for the data input, of shape [n_x, None] and dtype "float"
    Y -- placeholder for the input labels, of shape [n_y, None] and dtype "float"
    """
    X = tf.placeholder(shape= [Nfeat, None], dtype= "float64" )
    Y = tf.placeholder(shape= [Nlab, None],  dtype= "float64" )

    return X, Y
