>>> x=[[1,2,3],[23,13,213]]
>>> xx=tf.reduce_sum(x)
>>> sess.run(xx)
255
>>> x=[90,10,8]
>>> tf.reduce_sum(x)
>>> sess.run(xx)
108
>>> x=[[1,2,3],[23,13,213]]
>>> xx=tf.reduce_sum(x)
>>> sess.run(xx)
255
>>> x=[90,10,8]
>>> tf.reduce_sum(x)
>>> sess.run(xx)
108