A firm orders office products from a distant country and can order only once for the entire season. This ordering follows the assumption of the newsvendor model. The firm forecasts that their average demand is likely to be $8500$ units. The firm believes that the possible variation in demand is normally distributed and the standard deviation is $650$ units. The office product cost is $$3,$ the selling price is $$4.$ If a local reseller agrees to buy back the unsold products for $$1,$ what is the ideal order quantity for this office product?