A product made in two factories, P and Q, is transported to two destinations, Rand S. The per unit costs of transportation (in Rupees) from factories to destinations are as per the following matrix:

Factory P produces 7 units and factory Q produces 9 units of the product. Each destination requires 8 units. If the north-west corner method provides the total transportation cost X(in Rupees) and the optimized (the minimum) total transportation cost is Y(in Rupees), then(X-Y), in Rupees, is