某超市为了促销，采用了购物打折的优惠方法，若顾客购物的金额f：1000≤f＜2000，95折；2000≤f＜3000，9折；3000≤f＜5000，85折；f>5000，8折。编写程序，输入顾客的购物款计算出应付款-For a supermarket promotion, use discount shopping discount method, if the amount of customers shopping f: 1000 ≤ f < 2000,95 break　2000 ≤ f < 3000,9 break　3000 ≤ f < 5000,85 fold　f>　5000 , 8 fold. Write a program, enter the shopping section to calculate the payable