Sue has sourced four wholesalers from where she will buy most of her stock, including arrangements with two suppliers for 30 days credit, while the others are Cash on Delivery (COD). She has purchased her store fittings and has $15000 of stock (Stock at Valuation - or SAV), with a further $10000 on 30 day credit). The business has an operating cash reserve of $20000. How many wholesalers require terms of cash on delivery?