Ticket Booking System

This problem requires you to simulate a simple ticket booking system for a movie theater. You need to implement a system that supports the following operations:

• book c k: Book k tickets under the customer name c.
• cancel c k: Cancel k tickets for customer c. If the cancellation number exceeds the current booking, set the ticket count for that customer to 0.
• check c: Print the number of tickets currently booked under customer name c.
• summary: Print a summary report where the first output line shows the total number of tickets booked, i.e. $S=\sum_{c}\text{tickets}(c)$, and the following lines list each customer with a positive ticket count in alphabetical order in the format customer: tickets.

You must read input from standard input and output the results to standard output.

inputFormat

The input begins with an integer n representing the number of operations to process. The following n lines each contain one of the following commands:

• book c k: Book k tickets for customer c.
• cancel c k: Cancel k tickets for customer c.
• check c: Output the number of tickets booked by customer c.
• summary: Output the summary of all bookings.

Parameters are space-separated. Customer names are strings without spaces and k is a positive integer.

outputFormat

For each operation that produces an output (check and summary), output the result in the order that the operations are given. For a check operation, output a single integer representing the number of tickets booked for that customer. For a summary operation, output multiple lines: the first line must be the total number of booked tickets, followed by each customer (with a positive ticket count) in alphabetical order; each line should be formatted as customer: tickets.

## sample

4
book Alice 5
check Alice
cancel Alice 2
check Alice

5
3

</p>