C++ coding assignment
Input:
3 files (F1, F2, F3) with synonyms.
* Format: `word1=word2 word3=word4`
* Separator between pairs: `=`
* Separator between synonyms: space `" "`
Processing:
* Read files in **parallel threads** (1 thread per file).
* Merge all synonyms together.
* Remove duplicates.
Output:
* Print groups of synonyms (words that are connected).
* Each group printed once.
* Words inside each group sorted alphabetically (lowercase).
* Provide option to sort ascending/descending.
