doctor fee calculation in python
age=[]
for i in range(20):
n=input()
if(n == ""):
break
elif(int(n) in range(0,120)):
age.append(int(n))
else:
print("invalid input")
exit()
fee=0
for i in age:
if i in range(1,17):
fee =fee+200
elif(i in range(18,40)):
fee=fee+400
else:
fee=fee+300
print(fee)