A shopkeeper buys five products each at a cost of Rs. A per product. He marks up the price of the the first product by 10 percent and provides a discount of 10 percent and sells the product. He marks up the price of the the second product by 20 percent and provides a discount of 20 percent and sells the product. He marks up the price of the the third product by 30 percent and provides a discount of 30 percent. He marks up the price of the the fourth product by 40 percent and provides a discount of 40 percent . After selling four products he realises that he is losing money. He has already promised that he will provide a discount of 20 percent on the 5th product. How much should be the mark up percentage on the fifth product so that after he sells all the five products he neither ends in profit nor loss ?