The rear window of a van is coated with a layer of ice at 0°C. The density of ice is 917 kg/m3, and the latent heat of fusion of water is 3.35 x 105 J/kg. The driver of the van turns on the rear-window defroster, which operates at 12 V and 18 A. The defroster directly heats an area of 0.35 m2 of the rear window. What is the maximum thickness of ice above this area that the defroster can melt in 3.2 minutes?