class Cashier {
    int count=0, order;
    double discountProduct;
    Map<Integer, Integer> map = new HashMap<>();
    
    public Cashier(int n, int discount, int[] products, int[] prices) {
        this.order=n;
        this.discountProduct=1-(double)discount/100;
        for(int i=0; i<prices.length; i++){
            map.put(products[i], prices[i]);
        }
    }
    
    public double getBill(int[] product, int[] amount) {
        count++;
        int total=0;
        for(int i=0; i<amount.length; i++){
            total+=map.get(product[i])*amount[i];
        }
        
        return count%order==0? total*discountProduct : total;
    }
}