In the second programming assignment Exercise 3, X and Y are inputs with the following description:

`X -- list of integers, where each integer is a number that maps to a character in the vocabulary. Y -- list of integers, exactly the same as X but shifted one index to the left.`

Does the description mean that Y[i] = X[i+1], X[0] = 0, and Y[-1] = 0 (indicating ‘\n’) to line up with the expected input/output for one example for this language model? I’m confused as in optimize_test this is not the case:

`X = [12, 3, 5, 11, 22, 3] Y = [4, 14, 11, 22, 25, 26]`