Customer Service Call Handling

You are the manager of a call center, where calls from customers are managed in a queue. Each call has an associated priority (higher numbers indicate higher priority). Customers can either call in or hang up, represented by commands 'call <priority>' and 'hangup'. Your task is to process a series of commands and print the IDs of the customers in the order they will be served. Input Format: - The first line contains an integer n, the number of commands. - The next n lines contain the commands as described. Output Format: - A single line containing customer priorities in the order they will be served. Example: Input: 4 call 5 call 3 hangup call 7 Output: 7 5 3