sum=0

n=0

while True:

momey=input("請輸入金額 : ")

if momey=="q":

print("共計 ",n," 筆，總金額共 : ",sum," 元")

break

else:

sum +=int(momey)

n += 1

# 以下為折扣計算......

if sum>=3000:

discount=0.8

elif sum>=2000:

discount=0.9

elif sum>=1000:

discount=0.95

else:

discount=1

# 輸出折扣後金額......去掉小數點

sum=round(sum*discount)

print("結帳金額折扣後為: ",sum," 元")