Supershop billing details

using System;

public class Program
{
    public class Product
    {

        public string name;
        public int price;
        public string category;
        public int discount;

        public void assign(string na, int pr, string cate, int dis) {
            name=na; pr=price; cate=category; discount = dis;
        }

    }
    public class bill
    {
        public int get_bill(Product product1, Product product2, Product product3)
        {
            int totalbill = 0;
            totalbill+=(product1.price-product1.discount);
            totalbill+=(product2.price-product2.discount);
            totalbill+=(product3.price-product3.discount);

            return totalbill;
        }
    }

    public static void Main()
    {
        Product[] Bill = new Product[3];


        Bill[0].assign("Keyboard",1000,"Accessories", 120);

        Bill[1].assign("Proccessor",10000,"Accessories", 1200);

        Bill[2].assign("MotherBoard",7000,"Accessories", 620);

        bill ob = new bill();
        Console.WriteLine(ob.get_bill(Bill[0], Bill[1], Bill[2]));
    }
}