Discount for 1st item with Quantity Based Discounts & Prices for WC plugin?

Hi,

does anyone know if is it possible to get a custom discount rule for my woocommerce store with Quantity Based Discounts & Prices for WooCommerce-plugin as follows: a customer gets 15 % discount for every first item in the cart. For example : customer buys 3 pcs of product A and 1 pcs of product B. The customer gets the 15% discount for 1 item of the product A and also for the product B. So there is no limit how many pcs of each items you are buying, the first one always gets the discount.