You are given three sorted arrays A$,$ B$,$ and C each having n numbers. You can assume that you can compare two elements from AU BUC in O$(1)-$time. Let k be an integer. Design an algorithm that outputs the k$-$th smallest element of AU BUC. The running time of your algorithm must be faster than O$($n$).$ Try to optimize the running time of your algorithm as much as possible.