Churu and his Sequence

Given a list of N numbers, say A[1..N]. And a set of integers S. Each A[i] belongs to the set S. Being said that let us first define if a array is ‘good’ or not good. We say a array, Ar[M] of size ‘M’, good if for every pair of index (A[i] !=A[j] and 1 ≤ i, j ≤ M) there exist some index k (1 ≤ k such that at-least one of the following condition hold - Ar[k] = Ar[i] and A[k+1] = Ar[j] - Ar[k] =