The straight-line method for computing the yearly depreciation in value D for an item is given by the following formula:

D=(p-s)/Y

where P is the purchase price, S is the salvage value, and Y is the number of years the item is used. Write a program that takes as input the purchase price of an item, the expected number of years of service, and the expected salvage value. The program should then output the yearly depreciation for the item.