from sys import exit

package = input("What package have you subscribed to? ")
package = package.lower() #why is this done?

#use if statements to check if package was valid? (a, b, or c)
    

hours = input("How many hours did you use? ")
hours = float(hours) #why is this done?

while hours < 0:
    print("Hours must be positive (or zero)")
    hours = float(input("How many hours did you use? "))

while not ('a' <= package and package <= 'c'):
    print("You did not type in a valid package.")
    package = input("What package have you subscribed to? ").lower()

if package == 'a':
    base_charge = 9.95
    additional_charge = 2
    hours_paid_for = 10
elif package == 'b':
    base_charge = 13.95
    additional_charge = 1
    hours_paid_for = 20
elif package == 'c':
    base_charge = 19.95
    #additional_charge = 0 #don't need because not used for package c below
else:
    
    exit()


    

if (package == 'a' or package == 'b') and hours >= hours_paid_for:
    total_charge = base_charge + (hours - hours_paid_for)*additional_charge
else:
    total_charge = base_charge
print(total_charge)

#note that this doesn't exist for package c
#print(hours_paid_for)