Consider a cell during the depolarization and repolarization phases. A system is defined such that it includes a patch of the membrane measuring 0.5 m2 and the interior of the cell directly below this patch. During the depolarization phase, which lasts 0.2 ms, sodium ions are estimated to flow into the neuron at a rate of 6.7 1015 ions/(cm2s). During the repolarization phase, which lasts 0.3 ms, potassium ions are estimated to flow out of the neuron at a rate of 3.8 1015 ions/(cm2s). After both phases, what is the accumulation of positive charge inside the cell?