How do we review a district court's interpretation and application of the Guidelines de novo?

We review a district court's interpretation and application of the Guidelines de novo, see United States v. Adler, 52 F.3d 20, 21 (2d Cir. 1995) (per curiam), and its factual findings for clear error, see United States v. Mulder, 273 F.3d 91, 116 (2d Cir. 2001). "If we identify procedural error in a sentence, but the record indicates clearly that the district court would have imposed the same sentence in any event, the error may be deemed harmless, avoiding the need to vacate the sentence and to remand the case for resentencing." United States v. Mandell, 752 F.3d 544, 553 (2d Cir. 2014) (per curiam) (internal quotation marks omitted).