How do I do this?

Does the first array appear as a sequence within the second array? If so, return the first index where the first array can be found within the second. Otherwise, return -1. We will say that an empty array can be found in any array beginning at index 0. Find sub Array ([5, 12], [2, 7, 5, 12, 14]) rightarrow 2 find sub Array([9], [4, 9, 7, 9]) rightarrow 1 find Sub Array([4, 8], [4, 7, 8, 9, 10, 8, 4]) rightarrow -1