while(1):
print("Welcome! How many people, please?\nEnter 'quit' to end the program.")
resp = input()
if resp == 'quit':
break
else:
number = int(resp)
if number<1 or number >20:
print('数字不合法')
break
if number<=4:
print('Your small table is reserved!')
elif number>4 and number<=6:
print('Your middle table is reserved!')
elif number>6 and number<=10:
print('Your large table is reserved!')
else:
print('Sorry, there is no free table that seats over ten persons.')