Chef and Function

Chef has a sequence A containing N integers A1, A2, ..., AN and an integer K. For each pair (l, r) such that 1 ≤ l ≤ r ≤ N, Chef defines functions MIN(l, r) = min(al, al+1, ..., ar) and XOR(l, r) = al xor al+1 xor ... xor ar. Then, Chef defines a function f(l, r) = MIN(l, r) ∙ XOR(l, r). Chef wants to know the K-th smallest possible value of f(l, r). Formally, consider a sorted array of all N(N+