Concurrent URL Status Fetcher

Your task is to develop a program that reads a list of URLs from standard input and concurrently fetches their HTTP status codes. In a real-world scenario, one might perform network requests; however, for this problem, you will simulate a network call as follows:

• If the URL contains the substring https://httpbin.org/status/, then the status code is the integer immediately following this substring. For example, for https://httpbin.org/status/200, the status code is 200.
• If the URL does not match this pattern, then it is considered unreachable and you should output unreachable.

You are encouraged to implement your solution using concurrent programming techniques (e.g., threads) to handle a large number of URLs efficiently.

inputFormat

The input is given via standard input. The first line contains an integer N (1 ≤ N ≤ 10⁵), which represents the number of URLs. Each of the following N lines contains a single URL as a string.

outputFormat

For each URL provided in the input, output a line that contains the original URL followed by a space and then the corresponding HTTP status code or the string unreachable if the URL does not match the expected pattern.

## sample

2
https://httpbin.org/status/200
https://httpbin.org/status/204

https://httpbin.org/status/200 200
https://httpbin.org/status/204 204

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