How to use predict value from previous example as input for the next prediction

Hi,



If I use the previous known label value as the input in the next prediction in the training and hence the model, how can I generate the forecast as I need the prediction as the input for the next forecast.



As the example below, input is the previous known label value (e.g. #2 input = #1 label). 1-4 are the training set. I would like to generate the forecast for 5-7. #5 label can generated as #4 label is known. After #5 label is generated by Apply Model, how can I use it as #6 input to apply the model and so on?



# input label

1 a b

2 b c

3 c d

4 d e

5 e ?

6 ? ?

7 ? ?



Thanks