3694. Distinct Points Reachable After Substring Removal

You are given a string s consisting of characters 'U', 'D', 'L', and 'R', representing moves on an infinite 2D Cartesian grid. - 'U': Move from (x, y) to (x, y + 1). - 'D': Move from (x, y) to (x, y - 1). - 'L': Move from (x, y) to (x - 1, y). - 'R': Move from (x, y) to (x + 1, y). You are also given a positive integer k. You must choose and remove exactly one contiguous substring of length