Display 16 random images and their labels in the training data set as subplots of 4x4 grids. Set the figure size of the entire 4x4 grid as figsize=(5,6) The result is supposed to be of the following form (but with different images).

(Hint: In the for loop, generate a random integer k between 0 and 60000 and display train_xs[k] and its label)