Lossless English Text Compression and Decompression

In this problem, you are required to design a lossless compression and decompression algorithm for English text.

Your program must implement both the compressor and decompressor functionalities:

• Compressor: It takes as input a string made up solely of lowercase English letters and outputs a compressed string. The compressed string may consist of uppercase letters, lowercase letters, and digits, but no other characters are allowed.
• Decompressor: It takes as input a compressed string and recovers the original string of lowercase letters.

Note that all inputs provided to the compressor are derived from English texts generated by GPT-3.5-turbo (with all letters converted to lowercase). This property is key to solving the problem.

Input Format: The first line of input is a single character indicating the operation: 'C' for compression and 'D' for decompression. The second line contains the string to be processed. For example:

C
hello

In this problem, a valid but trivial solution is to simply output the input string, which satisfies the requirements of a lossless algorithm.

inputFormat

The input consists of two lines:

1. The first line contains a single character: 'C' (for compression) or 'D' (for decompression).
2. The second line contains the string to be processed. When compressing, the string consists only of lowercase letters; when decompressing, the string may include uppercase letters, lowercase letters, and digits.

outputFormat

Output a single line containing the result of the operation. For compression, output the compressed string; for decompression, output the original string.

sample

C
hello

hello