06 Shopping Exam

command = input()
names_dict = {}

while not command == 'shopping time':
    action, key, value = command.split(" ")
    value = int(value)
    if key in names_dict:
        names_dict[key] += value
    else:
        names_dict[key] = value

    command = input()

command_buy = input()
while not command_buy == 'exam time':
    action, key, value = command_buy.split(" ")
    quantity = int(value)
    if key in names_dict:
        if quantity <= 0:
            print(f"{key} out of stock")
        elif quantity > names_dict[key]:
            quantity = 0
        else:
            names_dict[key] -= quantity
    else:
        print(f"{key} doesn't exist")

    command_buy = input()

for key, value in names_dict.items():
    print(f"{key} -> {value}")