Chef and Line

Chef has a sequence A with length N and a line given by the equation y(x) = k · x + b. Let us say that an element Aj is reachable from another element Ai if the point (Ai, Aj) is lying above or on the line y(x), i.e. if Aj ≥ k · Ai + b. Consider an arbitrary subsequence of A; let's denote it by B. Subsequence B is called good if its elements can be reordered in such a way that for each valid i, B